SCUBA Blog

Tanks a lot

2007-09-30T23:13:00.000-07:00

Making a purchase decision on your own SCUBA tank can be a confusing one. Aluminum or steel? High pressure or low pressure? What size? Here is what I learned in doing research for a purchase decision:

Aluminum versus steel:
As a primary/back cylinder, the common aluminum tank (AL - the Dept of Transportation code for an aluminum constructed compressed gas cylinder) is the 80 cu.ft. A 100 cu.ft. can also be found. There is one primary advantage of AL tanks - they cost less than steel tanks. Other than that, most people go steel over AL as a tank they wear on their back (a stage bottle or pony is a different story). In terms of buoyancy, AL tanks are not very negative when full and are positively buoyant by about 4 pounds when at 500 PSI. That means packing more lead in order to sink. One case where an AL can be beneficial is in the case of warm water diving where large capacity steel tank will have enough negative buoyancy that a diver in a thin wetsuit could still be negative even after dumping their weights. That is not a concern for me since I am a big guy and get cold easy, so I have more neoprene than most people and all that foam requires more weight to sink me, and where I live I will only be doing cold water diving with the tank. There are neutral buoyancy 80 cu.ft. AL tanks on the market, but they are more expensive than regular AL tanks. AL tanks have very poor resale value, and they tend to fail hydro long before a steel tank will. Most AL tanks are rated (will be full at) 3000 psi, with some rater at 3300 psi.

Steel (AA - the Dept of Transportation code for a steel constructed compressed gas cylinder) tanks have a thinner wall than AL tanks. Most AA tanks are more negative (for a given volume) at the beginning of the dive than AL tanks, and AA tanks end the dive still negative while weighing similar to an AL tank of same compressed volume on land. AA tanks come in a wider range of volumes and sizes than AL tanks do. AA tanks have good resale value because they last a long time and therefore hold their value well. It isn't unheard of to buy a new one, dive it for a bit and sell it for 80% of what was paid for it. AA tanks cost anywhere from 2 to 3 times the cost of an AL tank.

High pressure or low pressure?
AA tanks pretty much come in two flavors, low pressure and high pressure. Low pressure (LP) is defined as 2400 psi. LP tanks on the market today have a plus (+) rating, which means they can be filled 10% over the 2400 psi, or to 2640 psi. High pressure (HP) tanks are rated to 3442 psi. HP tanks are relatively new to diving; they have been around since 2003 or so. Here are some fundamentals on LP or HP tanks before we move on:

An advantage of a LP fill is that you know you will get a complete fill no matter where you go since all fill stations can fill to LP. Also, the tank doesn't get as hot as a HP tank so there is less settling (lowing of tank pressure from drop in pressure) after a fill.

HP tanks are great in that you get a lot of air in a compact cylinder, but they need to be filled slowly and preferably submerged in water to control heat so there will be minimal settling. There are probably some fill stations out there that cannot go higher than 3000 psi, but all that I have seen recently can give a HP fill. The problem is if you get a quick fill, like on a dive boat or in a shop at a dive location where the tank is not going to be in water during the fill, then you will end up with a short fill. I was talking to someone who recently went on a live-aboard where his fills would consistently settle to around 3100 psi.

In the past many people would over fill their LP tanks to 3000 psi and above. The nickname for this is a "cave fill" since cave divers want the maximum amount of gas volume in the minimal amount of space. I think it is also because HP tanks haven't been around very long, so what they were essentially doing was creating HP tanks from LP tanks. To do this they would need to add another burst disk to the tank. Over filling is a practice you can't count on getting. Everyone is so safety paranoid today that even though there is a past record of the practice working, tank manufacturers and many fill stations will not condone it.

Buoyancy characteristics of LP and HP tanks are about the same

The price between LP and HP tanks are about the same for a given volume

A HP tank does not need to be filled at HP all the time. It can be filled “short” to mid or low pressure, but the volume will be less. For example, according to a steel tank information page on the DiveRiteExpress.com web site, a HP 100 will be an 80 at 2640 psi, and an 89 cu.ft tank at 3000 psi.

I read one belief that HP tanks strain equipment in the upper psi range of the fill, and that it is better to fill HP tanks to about 3000 psi.

Since a HP tank can also become a LP tank (with smaller volume), I decided to choose a HP tank of appropriate size so that the LP volume would meet my needs. That way I would always get enough of a fill that I need for most dives. My plan is to have it filled to around 3000 psi the majority of the time, and then occasionally take it up to 3442 psi if I need the extra volume.

One disadvantage of a larger tank is if the volume in it is more than you need (i.e. you come up with a bunch of air left) then you are lugging around the extra weight of that air in the water. For example, a 130 tank when full is about 11 pounds heavier than when at 500 psi. If a diver consistently only uses 5 pounds of that air, then they are carrying around an extra 6 pounds that has to be compensated by having more air in their BC…and the more air in the BC the more buoyancy is hard to control. Why not just drop 6 pounds off the weight belt in that scenario? Proper weighting means the diver can hold a safety stop with 500 psi, so if you don’t breath the air in the tank, then it is just extra weight. So….the biggest tank on the market is not necessarily the best for everyone. It is more like – get the tank that has physical dimensions that fit you and that has a LP volume that will work for you, and then choose the fill based on what you will probably need for the dive. This is why a diver may choose to short fill a high capacity tank and turn it in to a LP tank.

See the Variable Capacity of Cylinders section on this page from Dive Rite Express: http://www.diveriteexpress.com/gas/steel.shtml

Tank dimensions:
Different capacity tanks have different dimensions. Some are close in volume but different in shape. The diameter of the tank will be either approximately 7.25 or 8 inches, and the length varies by tank. As an example of two similar volumes with different sizes, the XS SCUBA 120 cu.ft. is 7.25 inches by 28 inches long. Their 119 tank is 8 inches by 24 inches long. For comparison, an AL tank is 7.25 by 26 inches. Length can play a part in comfort and trim. A shorter, fatter tank will put more weight high up on the diver’s torso. A tall diver probably wants to get a longer tank since they have a longer torso, and a shorter diver probably wants a shorter tank so they don’t feel like is it hanging between their legs in the water. I am 6’4”, and I chose not to get the 120 as I believe anything longer than an AL 80 will feel a tad long on me.

Which size did I choose? I recently dived a LP 95 and a HP 100 and felt those volumes were the minimum I want to be able to do the slow ascents that I want to do. In terms of volume, a 119 is perfect but it is a bit short for a tall person. I was torn between the 120 and 130 cu.ft. tanks as far as a purchase decision. I decided to go for the 130 since I was a little concerned about the length of the 120. So the 130 is three volumes in one tank – according to the Dive Rite Express web site regarding tank selection, a 130 is also a low pressure 104 and mid pressure 117. It all depends on how much air you put in it.

Additional reading:
Dive Rite Express page about choosing a tank
http://www.diveriteexpress.com/library/tanks.shtml

Dive Rite Express page about tank volumes
http://www.diveriteexpress.com/gas/steel.shtml

XS SCUBA specs page for their tanks
http://www.xsscuba.com/tank_steel_specs.html

Holy shark bait!

2007-09-29T11:24:00.000-07:00

Whoa! Apparently this pic is not doctored and is the real thing. I guess this shark is in the mood for a banana. I found a link to it at http://scubadiving.gadling.com. Here is the post URL:
http://scubadiving.gadling.com/2007/07/05/reason-451-why-im-afraid-of-the-ocean/

Blue screen of death

2007-09-28T21:57:00.000-07:00

This is a Sun commercial against Microsoft that was apparently banned from TV. I found it on http://www.scubaherald.com/.

Self-reliance

2007-09-28T14:49:00.000-07:00

I like the idea of being more self sufficient in the water so I can rely less upon whomever I have for a buddy. Not that I want to dive completely solo, it is just that even with a buddy you may very well be effectively diving solo. Here is why:
- One of the reasons for having is buddy is in the event of an out of air situation. That means the buddy is carrying my emergency air supply. What if they don't manage their gas supply well enough to leave a little extra for me? What if I am bigger than the buddy and I suck down their tank? What if they are ahead of me and I can't catch them on one breath of air?

- Counting on a buddy to help me means relying upon them to have the skills and the mindset to do it. To me, that means everyone should aim to be at least rescue trained.

- In the past I have gone on dive charters alone and been assigned an "insta-buddy" wherein the boat divemaster says everyone needs a buddy and pairs up buddy-less divers. How much can I rely upon this other person?

I remember one insta-buddy incident in particular. I was on a dive charter in the Turks and Caicos islands and I got assigned an insta-buddy on the boat. After we jumped in to the water, we descended and he took off. He never looked back. I followed for a bit, but when I realized I couldn't catch him, I gave up and just had a nice solo dive. Back on the boat I didn't bother saying anything to him because after seeing what kind of buddy he was I felt safer diving solo. I had my underwater housing for my 35 mm camera and a big strobe unit to drag around, so I liked the idea of just cruising around and snapping some pics. Of course this brings up the issue of having mutual dive objectives, so my bad for not discussing them...but he should not have taken off like that. The next dive was the same thing. We descended from the surface over the wall. He flips heads down and starts finning hard straight down along the wall. I thought maybe he saw something, so I start following. At 80 feet I stopped and watched him disappear below me. I ascended a bit and had a nice solo wall dive. I would have been putting myself at risk if I were to keep up with him. He was putting me at risk by not being a buddy. Screw him.

What is involved in being more self-reliant? There is solo diving and then there is being self-reliant. Being self-reliant is part of diving solo. I want to be more self-reliant and still dive with someone else. It just means I don't need to rely upon them as much, and if they are more self-reliant then they don't need to rely upon me as much either. I see steps towards self sufficiency being:
- Carrying a larger primary air supply, and a redundant secondary air supply

- Proficiency in underwater skills

- Comfort underwater in dealing with a variety of conditions and incidents

- Knowing your limits

When I searched for other sources of info on the internet about solo diving, I found the objectives they list corresponds to my list.

Air supply: Under the buddy system, my buddy carries my emergency air supply. Self-reliance means I carry my own. I think this means having a larger primary tank so I have extra time to figure out how to free myself if I get tangled up in something, and it also means carrying a redundant air supply and regulator in case I have a first stage failure or go out of air. I recently purchased a 40 cf tank and regulator setup and the redundant setup, and a 130 cf for my primary. On the subject of air supply, I also believe in using nitrox in order to reduce nitrogen loading. I will sling the 40 like a deco bottle. A 40 cf tank might sound kind of big compared to the compact Spare Air units out there, but I am a big guy and therefore have a larger lung capacity. I want enough air to be able to make a slow and safe ascent from a deeper dive. I think of a Spare Air more as an escape bottle to get a few breaths in while doing a controlled emergency swimming ascent (CESA). I also have other plans for that 40 - like filling it with a richer blend of nitrox than my back gas and using it as a washout gas while ascending (once I am above the max depth for the nitrox mix).

Proficiency in underwater skills: Being able to maintain composure if someone accidentally knocks my mask loose with their fin or similar incident means extra safety for me since I won't have the urge to bolt to the surface or grab on to a buddy. Being able to remove my BC underwater to help untangle it is important too. For me, taking the Divemaster course to re-visit the open water skills have helped give me assurance that I can handle these kinds of incidents on my own. Another skill is being able to do a free ascent while having control over the ascent so I can decide my ascent rate and where I am going to do my safety stop. Navigation is important as well; being able to make a nice underwater tour and end up back at the boat makes for a nice dive, as opposed to ending the dive with a long surface swim through kelp.

Comfort underwater in dealing with a variety of conditions and incidents: To me this means having some experience in dealing with a number of conditions, like current, kelp, low visibility, etc.

Knowing your limits: Experience will give some indication of what your comfort level is for a number of things. This is not only personal limits, but also adhere to recreational diving limits. I physically feel better after making a slower than "normal" ascent, so I like to incorporate a slow ascent in to my dive plan.

Related links:
The Buddy System Reexamined
http://cisatlantic.com/trimix/other/solo2.htm

Going Solo - The Solo Diver Debate
http://www.o2technicaldiving.com/articles/going_solo_the_solo_diving_debate/

Solo Diving the and Recreational Diver, Part 1
http://www.airheadsscuba.com/soldvrarta.pdf

Solo Diving and the Recreational Diver, Part 2
http://www.airheadsscuba.com/soldvrartb.pdf

Safety stop

2007-09-27T10:01:00.001-07:00

A note on the "recommended safety stop." We know that recreational no decompression limit (NDL) diving is "no decompression diving." NDL diving does involve making a "safety stop." How is a safety stop difference from a deco stop? They are both doing the same thing - letting the body deal with nitrogen bubbling out from an ascent, and to do it at a depth that keeps the bubbling under control for the body to off-gas it through the lungs for a given amount of time until enough nitrogen has been gotten rid of to make it safe to continue ascending.

Deco diving involves multiple deco stops at various depths in order to complete the ascent, and these stops are mandatory and with a glass ceiling. Even though NDL tables are set up so that a diver in trouble can bailout to the surface, whereas the deco diver has to deal with the problem at depth, I wonder if recreational divers often skip the safety stop because it is something that is recommended but not seem by them as being mandatory? My training emphasized that a safety stop is always part of the dive, so really all recreational dives are all decompression dives with a minimum 3 minute deco stop at 15 feet.

Links to info on CO2 and diving

2007-09-26T12:16:00.000-07:00

I found some links regarding carbon dioxide and how it affects us while diving:
ACCLIMATIZATION YOU DON'T WANT - CARBON DIOXIDE
http://scuba-doc.com/CO2acclim.pdf

CO2 Risk Management Summary
http://www.cisatlantic.com/trimix/AQUAcorps/mix/CO2Summary.htm

CARBON DIOXIDE AND ITS EFFECTS ON DIVING
http://www.airheadsscuba.com/archives.htm#co2

Now diving dry

2007-09-25T16:20:00.000-07:00

I haven't been too fond of my Pinnacle Arctic wetsuit and have been on the search for something that will suit me better. I was on the fence as to whether or not to go dry. Having a dry suit certainly makes things more comfortable and convenient for California diving, but cost was an issue for me. Along with the cost of the suit there is the cost of undergarments, regular seal replacements on the suit, and the chance of tearing a seal while on a trip. I found a DUI TLS SE suit on sale at a local dive shop (LDS) near me, so I pulled the trigger.

I initially bought the Pinnacle Temperate fleece undergarment for a Channel Islands live-aboard trip. I went with fleece since they are cheaper so I could kind of see what I like and don't like in the cheaper stuff and go from there. I also brought some middleweight REI thermal long undies, a fleece shirt and a Primaloft vest to add to the Pinnacle if it wasn't enough.

The water temps in the Channel Islands were in the mid 60's and I was OK with the fleece with the middleweight undies. I added the Primaloft vest on one shallower dive where the temps were near 70 deg F, and I got a little warm on that dive. What I didn't like about the fleece is it is big and bulky. It doesn't pack very small either.

From reading online reviews and studies about undergarment thermal qualities, I decided to go for a synthetic loft insulator. Thinsulate is used in many undergarments, but in the world of outdoor clothing Thinsulate is kind of old skool stuff. I believe it is used for diving wear because some of the properties that make it less desirable for outdoor wear do not count against it as much for dry suit wear...and may even help it (like how it is heavier than other insulators and doesn't compress as much). I wanted to go for a higher loft insulator that would compress more than Thinsulate so that when I dump air from the suit I would lose more buoyancy and therefore (hopefully) be able to pack less weight for keeping control between 15 feet and the surface. One property to a higher loft insulator is its insulating properties are more affected by the amount of air in the suit. This can be a positive or a negative depending how you look at it. It is positive in that the undergarment has a wider thermal range over which it works, the drawback is you have to put a little more air in it than a denser insulator to get good insulation.

I got bit by the dry suit bug and made a SCUBA addiction buy of the Dive Rite Primaloft jumpsuit. I then took it to San Diego for diving as well as to Monterey. Water temps were colder. Monterey was its usual 55 deg F. With the Dive Rite suit and thinner leg undies and just the medium weight shirt undie, I was fine. It also packs small and is nice and light. It is basically a sleeping bag that you wear. It is pricey, but that is dry suit diving.

Overall, I like diving dry much more than wet. My wetsuit was too cold for Monterey, and with the dry suit I am fine. On the live-aboard trip I did all but one of the dives. In the past I tended to skip more dives when diving wet...especially the night dives.

Divemaster certification

2007-09-25T15:54:00.000-07:00

I recently completed the PADI Divemaster certification. I was interested in taking the course as part of my initiative to be a better diver; I liked the idea of revisiting and mastering the basic skills from Open Water (OW) class, as well as learning more of the science behind diving. Secondarily, it did sound interesting to perhaps work with a shop in assisting OW classes.

The DM course is basically four parts:

- Re-learning the basic open water skills to a higher level of critique than before, plus adding a few additional skills

- The study of the physics, physiology and other subject areas to have a better understanding of the principles behind the principles learned in the open water and other courses.

- An introduction to being a teaching assistant and run through of the programs a Divemaster can teach

- Review of some aspects of the Rescue course

The water skills part of the course focuses on the ability to have “demonstration quality” skills so that the Divemaster can demonstrate a skill taught in OW class to a student that may be having some difficulty and requiring one on one work. So all the fun skills from OW have to be reviewed and rehearsed to where the diver can not only completely nail the skill, but also do it in a way that shows the steps involved so a student can be watching underwater and be able to pick up on how the skill is performed. Some other skills are thrown in to help build task loading ability, like doing a BCD remove and replace underwater, and the lovely underwater gear exchange with a buddy while buddy breathing (the exchange of mask, BCD and fins). I found that mastering these skills gave me a higher level of comfort and confidence in the water. I also felt more self-aware…like how a golfer and bowler will become more aware of what is going on in their swing as they build experience. With more self-awareness comes the ability to better fine tune technique and equipment.

The bookwork part of the course gave me answers to why some things are they way they are. I particularly enjoyed the study of physics and physiology, like more information behind decompression theory.

A Divemaster can teach a few PADI programs, like Discover Snorkeling and Skin Diver. We took turns teaching skills from a course to the rest of the class.

The review of the rescue technique of dealing with an unresponsive diver found underwater is always good to run through while being graded by an instructor.

So did I get what I wanted out of the class? Yes - my primary objective was accomplished. Would I recommend it to someone who wants to accomplish the same objective? Absolutely.

Another vote for Nitrox

2007-09-24T10:21:00.000-07:00

Fast forward several months and several dives. I have since completed the PADI Divemaster certification. I have also been doing more diving. My recent dives have been:
- The dives for the Divemaster course
- Four dives in Cabo San Lucas
- Eleven dives on a 3-day live-aboard trip in the Channel Islands (Souther California)
- Seven dives in San Diego's "Wreck Alley"
- Two dives in Monterey, CA.

The two Monterey dives and five of the seven Wreck Alley dives were on nitrox, the other dives were on air. I have noticed that I seem to have overcome the headaches and other CO2 buildup symptoms I had before. Two of the Cabo dives were pretty strenuous. We were fighting a strong current to get back to the boat. I thought for sure the headaches and such were going to set in, but they didn't. The Channel Islands dives all went fine as well.

Having said that, I am even a bigger supporter of nitrox for recreational diving now that I was before. I was influenced by:
- Learning more about the physiological aspects of diving from the Divemaster course
- Conversations with a tech/cave/deep dive/trimix instructor
- My own increased focus on safety after a recent motorcycle accident
- Reading stories of divers getting DCS (the bends) while diving within recreational limits

Diving withing recreational (rec) limits involves nitrogen loading. Even though rec limits are no (mandatory) decompression diving, the more nitrogen a person has in their system, then the more opportunity for them to be one of the cases of people who get DCS even while following rec diving tables. The no decompression Recreational Dive Planner (RDP) tables are a model for a large cross section of people. They are not an actual representation of what exactly is going on in any human body, let alone your body. The less nitrogen you have trying to get out of your system, and the slower the pressure change from depth to surface (i.e. a slow ascent), the less likelihood of a person getting DCS (all other things being the same...because there are other things that lead to DCS, like exertion level, being cold and hydration).

From what I have learned, using nitrox reduces the amount of nitrogen being absorbed by the body when compared to using air for the same dive profile. The less nitrogen absorbed, the easier it is to get rid of it and the less chance of DCS. Another safety feature I see is in the case of making an emergency ascent. The less nitrogen I have taken on during the dive, the less likelihood of DCS being an issue after an emergency ascent with a missed safety stop.

One thing to keep in mind with nitrox is the max operating depth (MOD) of a given nitrox mix wherein the oxygen partial pressure in the body becomes toxic. The higher the oxygen percentage, the shallower the MOD. This mean you have to have an idea of the dive profiles you'll be doing in order to get the appropriate mix percentage.

For a given dive profile within the no deco limits of the RDP air table, nitrox will give an increased level of being conservative with regards to nitrogen loading. If a person dives to the "edge" of the nitrox RDP tables (tables adjusted for the reduced nitrogen loading of a given nitrox percentage), then the only advantage nitrox is offering is either a longer bottom time or shorter surface interval than air, and there is no increased level of conservatism for avoiding DCS since the diver is pushing the limits.

The way I have been diving is to set my computer to nitrox mode and setting the conservative variable on my computer to its max value. One issue with using the conservative factor on the computer is that I can be well within no deco limits, but because of the conservative setting on the computer I end up in deco mode with the accompanying red flags and longer no fly penalty. This recently happened while doing a nice long and slow ascent from a 95+ foot dive. The computer didn't seem to credit me with the slower than 33 feet per minute ascent (from around 75% of my max depth), so according to the computer I had an eight minute deco obligation between 10 - 12 feet until I could finish the dive. Sure doing this "deco stop" was extra conservative and didn't hurt, but I would rather have more control over the planning of my conservative ascent and extra safety stop time. I think from now on I will leave my computer conservative variable turned off and just end the dive well withing the no deco time limit of the gas mix I am diving. Even though my computer does not credit me for a deep stop or a slow (10 foot per minute) ascent, I will still continue to incorporate a slow ascent in to my dive plan and just know that the ascent is just another area of conservatism for me while staying within the no deco time of the computer.

Why I like Nitrox

2007-05-18T10:26:00.000-07:00

Nitrox seems to be a somewhat debated/controversial issue in recreational diving. I think the controversy is around what the expected benefits are. For example, there are rumors/opinions that Nitrox makes you warmer than if you were diving with air. When I inquired about Nitrox certification at my local dive shop, one of their questions was along the lines of "What are you trying to achieve with Nitrox?" I like that they asked that...like they are looking out for the consumer/diver to make sure the diver will actually get what they think they are going to get.

There is one and only one benefit to Nitrox as stated by PADI and other dive organizations, and that is that, when compared to a dive profile using air, you get either a longer bottom time or a shorter surface interval. All other benefits are opinions, topics for debate and subjects of personal experiences.

What I was wanting to get from Nitrox was some alleviation from the headaches I get when I finish a dive. I am pretty sure it is caused from CO2 buildup. I don't skip breathe or use other methods to conserve air. I am not trying to compete with myself or others on how long I can stay down. I try to keep my breathing as natural as possible, which ends up being a deep breath in and a slow exhale...then repeat. Still, I tend to get ill...and the headaches are often accompanied by nausea. When I was reading up on the CO2 thing, it seems some people are just more prone to CO2 buildup in their body, and I guess I am one of them. I hoped Nitrox would help make diving more enjoyable by feeling better after a dive. So....I got the Nitrox certification and did some dives with and without Nitrox. I did notice a difference and was getting the benefits I was hoping for.

This relates to my previous post about a dive operator saying that you don't need Nitrox for a dive. That may be true in terms of the surface interval and dive planning for the boat trip for the day, but it is not true for the benefits I get from Nitrox. I see Nitrox as another piece of equipment for recreational diving, so let me have Nitrox just like I might want to bring a flashlight, camera, dive sausage, etc.

The owner of the shop where I got the cert from told me he likes Nitrox because it makes him feel less exhausted after being in the water most of the day teaching students. He said that when under water for a class he is constantly going here and there to help students with their exercises, get them untangled fro each other, etc.

Rescue Diver certification

2007-05-17T11:02:00.000-07:00

I am catching up on this here since I let this blog go for a while. This past year I got the PADI Rescue Diver certification. Overall this was the most gradifying certification so far. I feel like a better diver now that I can more effectively help someone in an emergency situation.

The training includes scenarios for both underwater and surface-level emergencies ranging from a diver panicking to finding someone unconscious. It also includes search techniques for a diver who is not accounted for....which includes a combination of divers going in the water to look for the person, to having someone search the parking lot for the person's car to see (1) is the car there, and (2) is there dive gear in the car (i.e. are they are the bar eating fish and chips while everyone thinks they are in the water). We also did CPR certifications, as well as certifications on using the automatic defibrillators you see in airports.

Towards the end of the course, I also noticed I was much for efficient at getting geared up. I also noticed I felt more relaxed in the water, and buoyancy felt even more natural than before (assuming proper weighting).

Next stop - Dive Master.

Just found a recent dissenting opinion about Lahaina Divers

2007-05-16T12:41:00.000-07:00

I just came across this negative review of Lahaina Divers in Maui on the forum at scubadiving.com:
http://www.scubadiving.com/forum/tm.aspx?m=28242

Some points made in the post that I have comments on:
- Setting up your gear
- Food
- Dive Master leading the group
- Crew interaction with the divers
- Nitrox availability

Setting up your gear - the author complained that the crew did not set up the gear for the diver on the first dive, but then for the second. I agree with this practice - I think divers should set up their own gear for the first dive, and then then the crew will switch tanks for them in between dives. Having the divers set up their gear is kind of a test to see how "in practice" they are. If they are fumbling around and can't get the primary on the tank correctly or can't get their BC rigged correctly, then that tells the dive master (DM) to keep an eye on that person in the water. I like to set up my gear for the same reason why I bought my own gear - to know that it was done right...or at least the way I think it should be done ;)

Food - The author complained about the quality of quantity of food on the boat. I don't eat much before or in between dives since I am usually concentrating on not getting sick. I often come up from a dive feeling sick, so if anything I nibble on a little bread or some chips to get the sea water taste out of my mouth and to have a little something in the tummy. Given that, it still sounds like the dive shop should step up their game in terms of food. Instead of perishables that have to be delivered daily, they should try some packaged goods like energy bars...or something they can stock up once a week on and move from the shop to the boat on their own. They also shouldn't limit food. It is a vacation, people pig out. If someone wants to scarf half a box of cookies and then chuck them up over the side on the way back, then more power to them.

DM not leading the group on the second dive - Every tropical & Hawaii island dive I have been on has been led by the DM in order to prevent divers from touching stuff or from doing something foolish like sticking out their finger around the mouth of an eel (a good way to lose the finger). I wonder if a DM called in sick and they couldn't get a replacement, so they had to have the one DM stay on the boat (which they should for safety). My dives in Monterey and the Channel Islands were not guided. I wonder if dives on a tropical live-aboard are guided? I have done live-aboards in the Channel Islands - those were not guided, and the protocol is the boat is anchored at a location for so long...you can dive as much as you want or not dive at all during the time the "pool is open."

Lack of crew interaction with the divers - I find that unfortunate. Crew interaction builds upon the the diving experience. When I went out with Lahaina, I found the crew to hang with the divers, but that was a year ago; they probably have the same instructors but all new boat crews by now.

Nitrox availability - I almost had a similar experience. I ordered nitrox for most of my dives (there was one where I was going over 100 feet, so I did air on that one), but on some they were not planning on bring the nitrox tanks, and other others I had to remind them....which meant they had to scurry at the last minute to measure the O2 and get the tank on the boat. I find it interesting that they will say "you don't need nitrox on this dive" for shallower dives. It is all recreational diving; you don't need nitrox on any dive from a boat like that since the dive profile will be for people without nitrox and without computers. It is more of a comfort or "the way dive" kind of thing. I tend to feel sick less often when I use nitrox. They should allow it on any dive where you won't be going over 100 feet, or at least let divers know in the shop what their policy is on it instead of taking an order for it and deciding on their own to not fulfill the order. I think they do what they do because it takes extra time and effort to furnish nitrox for a diver, so they make excuses as to why it isn't on the boat when the diver ordered it in advance.

So does this cancel my overall positive review of them? Well, it does remind me of some things they need to improve upon, but overall I would still go to them again.

Lahaina Divers - review

2006-08-31T18:27:00.000-07:00

I dove with Lahaina Divers in the first week in August 2006 for my Advanced Open Water class. My search for a diver operator in Maui consisted of searching the internet, and then seraching on each dive operator's name to find reviews and/or comments. Here is the list that I ended up with:

Lahaina Divers
Maui Dive Shop
Turtle Reef Divers
Ed Robinson's Diving
Mike Severns Diving

From reading other reviews, customer opinions seemed to split these shops up in to two groups - Lahaina Divers and Maui Dive Shop being the big boat operators, and more boutique smaller vendors. I read reviews of people either reporting of or being concerned that the larger shops operate "cattle boats" wherein bigger boats mean more divers in the water at a site and therefore a more crowded dive experience.

My requirements were to satisfy my desire to do the Advanced Open Water (AOW) course while in Maui, as well as the ability to accommodate two teens who would be doing resort dives for a day. I would be staying north of Lahaina, so figuring convenience to the dive shop was a factor as well.

From visiting web sites and making some calls, I gathered that the Ed Robinson and Mike Severns diving operating smaller boats that would take one tour group of people (one dive master to lead the dive and 6 or so divers). Maui Dive Shop and Lahaina Divers operate bigger boats that can take two or so tour groups of people. I tend to favor bigger boats since you're more likely to have a real restroom, a little room to move around and less rocking and rolling to and from the dive site. I don't consider a 46 foot dive boat with two groups of divers to be a cattle boat. I do consider a cattle boat to be the large catamarans that carry 50 to well over a hundred people on snorkeling tours. You get that many people bobbing around in the water near the boat and it does feel crowded to swim around. The small single group dive boats probably have a toilet, but there is no enclosed restroom to use it, so my past experience has been you go through some saloon style doors and take a couple of steps down where you find the toilet/head. Of course the little doors don't come up very high, so you can tell when a guy is going #1 because everyone on the boat gets to see his back from about mid-back up. I like having a little more privacy as I am not the kind to go #1 in my wetsuit.

I was most impressed with Lahaina Divers when I called around asking about how they do the AOW and how resort dives are handled. With Lahaina I was put in touch with Steve Dimas, the instructor who would be teaching the class. He and I chatted on the phone and traded some emails following that. Overall this was a much more personal experience than the other operators, with Maui Dive Shop being the least personal (I was talking to a scheduler type of person). Maui Dive Shop didn't have any opensing for the AOW class for the week that I would be there. I think I was calling a week or so before our arrival date. As far as the resort dives, I was looking for a place that would do boat dives for the kids; not all operators do that.

Convenience to where we would be staying and proximity to the dive sites were another factor. Apparently most of the dive site, including Molokini, are south of Lahaina. The advantage of dive shops in southern Maui is they have less distance to travel before getting to the dive site, so they could beat the other dive boats there. One disadvantage of a southern Maui location is longer drive time from where we were staying. Being somewhere at 6:30am on vacation is a lot harder when there is an extra 30 minutes or so involved.

I ended up choosing Lahaina Divers based on the great experience of getting questions answered, their availability, how they handle resort dives, and the size of their boats.

Our experience with Lahaina Divers:
Our first day of diving was the resort dives for the kids and the first set of dives for my AOW class. We were able to go on the same boat and dive the same location, some place along the west coast a bit north of Lahaina. As far as feeling crowded under water, it wasn't an issue. After my instructor and I finished some exercises on one dive, we looked for the group under water with the kids; we didn't see them until we surfaced. If it were crowded, we should have been able to find them with ease.

The kids loved their SCUBA experience so much that our kid (he was there with his friend) decided to go for his Open Water certification while we were there.

My second dive trip was to Molokini. Molokini had significantly better visibility than the Maui coast dives. I saw the boats from some of the smaller dive operators, and having a real bathroom and having a bit of a rough ride on the way back made me appreciate having a bigger boat.

Our kid had a great experience with his Open Water class. Back at the dive shop, the people working the shop were great too.

Overall I would recommend Lahaina Divers to others looking for diving in Maui. I would use them again if and when we go back to Maui.

Advanced Open Water certification experience

2006-08-31T18:13:00.000-07:00

I decided to go for the Advanced Open Water (AOW) certification while on a vacation in Maui. I haven't taken any classes since my Open Water in 1998. My motivation for taking the class is I am interested in pursuing the Dive Master ranking.

I signed up with Lahina Divers to do the class, which consists of studying five 'specialties' (subjects) in the AOW book, completing the corresponding knowledge reviews, and then going on five dives. Each dive corresponds to a subject studied. The Deep Diver and Underwater Navigator subjects are mandatory, and then Lahaina Divers said they usually do Underwater Naturalist, Peak Performance Buoyancy and Boat Diver. I bought the AOW book from a dive shop local to my home prior to the trip and finished the knowledge reviews on the plane to Maui.

My AOW class was a private session since no other people signed up for a group class the week I was out there. The class consisted of four boat dives and one shore dive (UW Navigation).

Did I learn much? I think reviewing buoyancy principles and practicing some UW compass tasks was helpful, but I wouldn't consider this to be an advanced course in diving. I see it as "Open Water, Part 2." I wish I had taken AOW right after getting my Open Water certification. Over time I learned many of the skills taught in AOW just from limited experience.

Video cameras my change the game for UW photography

2006-08-19T14:56:00.000-07:00

I was chatting on the phone yesterday with someone at a marine camera store in San Diego. He was commenting on how the increasing quality of still pictures that can be taken from the newer HD video cameras is coming close to digital still cameras. I have a 3-chip video camera that can take 3mp stills. The pics it takes are not near the quality of the shots from my little Nikon Coolpix 5000 camera, most probably because of better post processing software in the Nikon than in the video camera. However, I can see that as technology advances that the video cameras may be able to capture a good enough unprocessed image wherein you can do sufficient post processing on a computer to get acceptable results.

SCUBA certifications

2006-08-13T23:33:00.000-07:00

My recent "advancement" in SCUBA certifications to Advanced Open Water, as well as recent readings about SCUBA accidents and criticisms of rapid SCUBA training programs got me thinking about what a diver is really qualified to do based on their training and experience. I got certified in 1998 and have around 50 dives to date with experience in various conditions from cold and low visibility to fighting current to nice tropical environments.

Here's how I see it, based on PADI courses and certifications:
The Open Water Diver certification is the first level of certification that makes you a "SCUBA diver." With this you can rent and buy SCUBA gear, dive on charter trips in resort locations and go off with a fellow diver to dive by yourselves where ever you want to. Getting this certification can be done in three days or so and with a total of five dives. Even though an Open Water diver is "allowed" to dive without professional supervision or in conditions unfamiliar to them, I think they should not attempt it without additional experience.

Without additional experience, I think an Open Water Diver certification qualifies a person to dive on chartered dives (where the dive is led by an experienced diver familiar with the site) under similar conditions under which they where certified. For example, if someone is certified in calm tropical waters, then more training should be taken before doing a cold water dive or diving in current. Cold water diving is more challenging in that the additional equipment can be claustrophobic, and the thicker wetsuits makes maintaining buoyancy more difficult. Diving in a current can be stressful in that the diver can feel like they can't make it to the boat and/or are being swept out to sea.

The Advanced Open Water is the next certification. It requires five dives and basically hones skills learned in the Open Water course, or develops new skills depending which areas of focus the student and instructor decide to take. I think the advanced class should be taken immediately after the Open Water class. The advanced class doesn't make you an advanced diver; it is really an Open Water part two course. After this course I believe a diver can start trying new things, like making the jump from warm to cold waters, or going from guided tours (where the guide has additional training in recognizing and handling underwater emergencies) to dives that are not guided and you and your dive buddy go on your own. An example of this would be a live-aboard dive trip where the boat ties off at a dive site for a couple of hours. Divers can make one or more dives there at their leisure as long as they are staying within safe margins of depth, bottom time and surface intervals. There would be a dive professional on the boat who will brief the divers on the dive site and handle any emergencies that come up (literally) like a diver surfacing and saying that his buddy is tangled up on something underwater, or a diver coming up unconscious or with decompression sickness.

I wish I had taken the advanced class right after the Open Water class. I have learned a lot just from diving experience, but it would have been am easier road to travel if I had the advanced class under my belt. Why did I take the advanced class now when I got certified in 1998? I am interested in pursuing either the Divemaster or Instructor ranking, so I need to make incremental steps to get there. So yes, experience can take the place of the Advanced certification, but having the Advanced is good when you don't have the experience.

After the Advanced Open Water is the Rescue Diver course, which is additional training in first aid and preventing, recognizing and treating in-water emergencies. I think the Rescue course is what makes a person a good or worthwhile dive buddy. There have been cases of divers dying in relatively shallow water (60 feet or so) due to botched underwater rescues such as buddy breathing when the diver should have been able to surface safely on one or less breath of air. There has even been a movement against having a dive buddy for two reasons (1) a buddy may cause more harm than good, and (2) being a buddy can impose some legal liability if you try to save someone and fail, or the other diver waits for you to save them (i.e. buddy breathing) when they should surface instead. I think the Rescue certification is the minimum divers should have if they are going on their own dive trip that doesn't involve chartering a dive boat or guide.