My wife and are have decided to get nitrox certified before we head down to Bonaire this year. The dive shop that is included in our travel package is Dive Friends. Do they have oxygen analyzers available for use?

Yes they do Travis!!!!!!!!!!

Sounds great. Thanks for the info.

Also welcome to BT and all it has to offer!!!!!!!!

Travis: Welcome to BT. It is a great community.

Good decision to venture into Nitrox (aka EAN, voodoo gas, etc.) What you will find most valuable, IMHO, is the ability to shorten your surface intervals and increase your bottom times. Basically depth limits are not a factor, particularly on Bonaire. Bottom time for most folks is more dependent on breathing rate than deco issues. Depending on depth for most folks the tank may not last long enough to max your bottom time.

NDL air at 60 ft = 55 min
NDL EAN32 at 60 ft = 90 min

NDL air at 80 ft = 30 min
NDL EAN32 at 80 ft = 45 min

Or on the bottom at the Hilma Hooker:
NDL air at 100 ft = 20 min
NDL EAN32 at 100 ft = 30 min

If you can make a tank last for the NDL on EAN32 at those depths you are in a small minority of divers.

Here is a surface interval idea based on 80 feet followed by 60 feet. I used the tables and assumed a constant depth at the max which is not realistic since we really do a multilevel dive. I could simulate a multilevel pattern with the eRDPML but would need to convert to EAD and it is too early in the morning for me to do that !!!

However this will give you some idea of SI benefits for a "typical" sort of BON dive:

Anyone correct me if you think these are off using the table RDPs for air and EAN32:

Air Dive 1 at 80 ft for 25 min = N for an ending PG
Air Dive 2 at 60 ft for 45 min
Minimum Surface Interval = 2 hours 19 min

EAN32 Dive 1 at 80 ft for 25 min = J for an ending PG
EAN32 Dive 2 at 60 ft for 45 min
Minimum Surface Interval - NONE. But if you came up long enough to change tanks (15 min for an SI) you could go back to 60 feet for 60 minutes.

Take the Nitrox course and enjoy but always plan the dive properly of course.

Thanks for the greeting. I have been following the boards off and on since last year when my wife and I began planning our last years trip to Bonaire. Great resource for information about the island and pretty much anything that goes on there. Being a different country it can be a little difficult to get answers about this or that or even finding exactly what you want. I have found the plethora of information on the boards supremely helpful.



Dan - What you have outlined is exactly why we are taking the Nitrox course. Last year which was my wife's and my first trip to Bonaire we got tangled up with running out of NDC on our Oceanic dive computer on a few occasions. But I guess that was part of doing 5-6 long dives per day.

Our typical scenario last year would be to hit 2 dives early in the morning, however with air we had to do around a 45 minute to 1 hr surface interval based on our dive computer. Then we would take a 2 hour lunch break to go get new tanks, eat some lunch and sit around waiting for the blasted nitrogen. Do it again in the afternoon and then again for a dusk and night dive. By the end of the day it got to be a lot of sitting around waiting for the nitrogen to offload and even then we ran into NDC limits 1-2 times and had to cut short our dives. Granted I set my rather liberal Oceanic computer back a couple ticks just for safety margins, however we were at our NDC limit.

LOL, I just realized I put in NDC rather than NDL everywhere. Guess my mind was somewhere else this morning.

Travis:

Yep - just the reason to dive EAN whenever possible. About the only time I don't use it is when teaching classes in the quarries. Dives are fairly short and shallow. Also I have to debrief and rebrief students between dives which more than meets SI requirements. And it is easier and less expensive to get air fills at the quarries than EAN.

And if I have been out for a few hours before a night dive I might not pick up a nitrox tank and just use air. Night dives are usually shallow and NDL is not an issue. Unless we do a night dive on the Hilma Hooker - then I will plan for EAN.

Since you are doing so many dives per day as you describe do be watchful of the oxygen levels you accumulate. Trust your computer BUT back that up with an eye on the DSAT table.

Dan - I'll definitely keep an eye on those oxygen accumulation levels. I have not gotten to the point in the book that discusses that, but I'll be there shortly.

Congrats on the decision to further your training and get 'geezer gas' certified. I wouldn't do a long dive vacation without it.

Obviously you still need to monitor your depth while on EAN 32 (the typical blend found at most resorts) as Bonaire's waters can run a tad deeper than the allowed safe limit at some sites.

Dive smart, dive safe and have a ball.

Travis, I am Geezer gas certified, and one thing to keep in mind.
It's not necessary to go out and buy a nitrox computer. By using the regular air computer while diving nitrox, you build in a safer top time cushion.

If you plan on diving 20 to 25 times in a week this translates into a sizeable off gasing period.

I've dove as much as 5 times in a day while on Bonaire and as a rule because of my age I don't dive deep anymore, max 60 ft.

I was told by some friends that they use nitrox because it doesn't make them so tired when they do 3-5 tanks a day. I was wondering if there was any truth to that or anyone else has noticed it. I am taking my class next month before I head to bonaire. I was sick of hitting my NDL on my new computer.

I used Nitrox for 20 dives in November and had a slight inkling that it might be a more invigorating gas, but decided it was more likely a placebo effect.
I was newly EAN certified at Buddy's, btw.

Certainly there are no negatives compared to air, assuming proper dive usage, and the surface interval benefit makes it a great thing for Bonaire-style diving.

I'm not sure that Bill's idea of using an air computer with Nitrox is generally a good idea, but if he's using EAN32 to max 60 feet and then uses air-computed surface intervals, I think he'll live...

Bill - My wife and I both already have our Oceanic Pro Plus 2s. I have had mine for a few years and picked my wife's fully loaded one up this last fall for under $400 brand new. Just couldn't pass it up at that price. I really couldn't imagine diving without one. Last year on our dive trip to Bonaire we fell just short of the 24 hr dive time mark at 23 1/2 hrs. That was partially because we were both sick the 1st couple of days, we are hoping this year to hit the ground flipping. ;)

Ryan - I have heard similar things however from what I have understood it is more of a placebo effect.

Randy - I couldn't imagine running into a situation where I would be above 1.4 ata on 32 EAN. Shoot I would be down digging a whole with a backhoe down at the Hilma Hooker 10 feet deep.

Tom, if you do dive nitrox and use your air tables. You have built in a safety net for your diving.

As it makes you more a live after diving my best guess would be because of the high oxygen content your breathing. Also my ex-wife was always up for some fun in the afternoon then just taking a nap. That's just my thoughts.

Travis--welcome to BT
What I've found is the log rhythm's in dive computers are not created equal, mine also seems to be on the conservative side.
Tom-Think about it, less nitrogen, more top time? Using an air computer with ean32 is much safer when doing repetitive diving in a short span. Yes, it's truly not accurate but it errors on the safe side.
The marine who taught me how to dive was a Naui, emeritus dive instructor. Bill is also my age and dives nitrox with an air computer.He feels that as we age this is the only way to go in regards to DCS safety!

I've been diving Nitrox for 10 years. I definitely feel less tired with it, even for just one dive, if it is deep (like 90+ feet). [Of course, I'm old, probably older than most of you!] Typically, in Bonaire, it is 4-6 dives a day, but few are deep, although they may be long. I keep pretty good surface intervals. I could not do a week like that on air. I know that for a fact; I've tried it (not in Bonaire).

As a Nitrox instructor (and technical Advanced Nitrox instructor), I understand but do not advocate the use of air computers (or nitrox computers set on air) while diving nitrox. If you want to not stay in the water as long as nitrox could allow, then do not. For those computers that indicate green-yellow-red nitrogen levels, just stay in the green. There are three reasons for this recommendation: (1) if you know that you can actually stay down longer, but don't know how much longer, then there is always the temptation to push the (air) limits, without actually having the info needed to push the limit safely. If the computer is set on nitrox, you have the info. (2), air computers do not track your oxygen levels. Admittedly, it is very difficult to exceed oxygen clock limits on NDL dives with <40% O2, but it is worth tracking, never the less. And (3), the most dangerous thing you can do with nitrox is exceed your maximum operating depth; that is clearly given on nitrox computers.

For most Bonaire diving, EAN32 with an air computer does indeed have a safety margin regarding Nitrogen loading.

The problem is Oxygen toxicity, especially if someone was to naively use an air computer with richer Nitrox on deeper dives. On Cozumel, for instance, you exit Punta Sur (Devil's Throat) at 130 feet. This would be a hazardous dive on EAN32.

This is the reason not to ever answer any of these questions, because somebody always know more then somebody else. I'm this I'm that!!!!!!!!!!

Patrick, go take a nap.

You know Mel, I was thinking the same thing!
Patrick has always seemed to be a nice guy and all of a sudden he gets grumpy--lol
Instead of taking a nap, he might need other therapy, previously discussed in this thread--lol
HAVE A GREAT DAY PATRICK!!!!!!!!!!!!!!

calm down Patrick.. there are a lot of other instructors here that ALSO know what they are talking about!! some teach by the books, some know the ins and outs.. lets hear it all..
I am Nitrox certified.. I dive air tables for safety but I also limit my depth.. I did the Devils throat on 28% with my computer set on Nitrox.. You just have to use your thinking caps a bit more before you dive.. PLAN YOUR DIVE, DIVE YOUR PLAN!!! and give yourself a little extra for user error.. or the consequences will not be good..

Ryan, I have not been able to find any hard evidence that diving using nitrox will make you less tired. Evidence be damned, I personally feel much less tired diving nitrox and use it for all my dives in Bonaire.

Freddie, I'm calm. I'll just leave it a lone.