Bottom time on drift dives

[DalTexDiver]

Like most everyone else on here, I dive 32 first dive and 36 the second, more shallow dive. Usually get about 50 to 60 minutes out of a tank. Most often when drift diving, run out of reef before I hit 500 to 750 psi. Like to come up with the divemaster if I can. Just an old man, macho thing.

 

[MMM]

Um, I don't think that is what most everyone else on here has said (2 posters said they dive with nitrox all the time or whenever they can). But I am sure I'll be corrected if I have not accurately captured the overall sentiment.

Like most everyone else on here, I dive 32 first dive and 36 the second.

 

[DandyDon]

Like most everyone else on here, I dive 32 first dive and 36 the second, more shallow dive.

I have never noticed anyone do 2 Nitrox tanks on the same boat trip. Maybe, just didn't notice.

I got to have 3 dives in a day before I'll bother with one Nitrox tank on the multi-level reef profiles.

 

[MMM]

May I introduce myself?

I did such a trip a year ago or so. We went south, around the most southerly point and back up (El Islolte) diving three tanks on our way back around, finishing at Palancar Gardens. SIs were done on the boat, as I recall. According to my log, 1st dive was 21% to 105 ft. for 50 minutes, second dive after a 1 hr. 10 minute SI was to 62 feet for 66 minutes on 32% nitrox and 3rd dive was to 57 feet for 85 minutes on 32% nitors after a 2 hr. 15 minutes SI. Scubawife, please correct if I have this wrong as you were on the same boat.

While I agree this isn't a "normal" profile, it's not beyond the pale with ops that offer big tanks (which include nitrox tanks) or unlimited bottom time. In fact, more like the norm.

I have never noticed anyone do 2 Nitrox tanks on the same boat trip. Maybe, just didn't notice.

 

[MichiganDiver]

I appreciate all the discussion about nitrox, as I will be heading to Coz in April and I am still a new diver.

I would also like to learn more about drift diving. My only other experience was in the Bahamas (Andros Island), where currents were not a concern. Please give me an idea what to expect on my drift dives, in terms of logistics (e.g. how does the boat find us and pick us up after the dive) and the actual dive experience (e.g. tell me more about down currents).

 

[scubawife]

May I introduce myself?

I did such a trip a year ago or so. We went south, around the most southerly point and back up (El Islolte) diving three tanks on our way back around, finishing at Palancar Gardens. SIs were done on the boat, as I recall. According to my log, 1st dive was 21% to 105 ft. for 50 minutes, second dive after a 1 hr. 10 minute SI was to 62 feet for 66 minutes on 32% nitrox and 3rd dive was to 57 feet for 85 minutes on 32% nitors after a 2 hr. 15 minutes SI. Scubawife, please correct if I have this wrong as you were on the same boat.

While I agree this isn't a "normal" profile, it's not beyond the pale with ops that offer big tanks (which include nitrox tanks) or unlimited bottom time. In fact, more like the norm.

And a great day it was! The first SI was on the boat between the two east side dives. Second SI was at Palancar beach. You and Jeremy dived the 2nd and 3rd tank on nitrox. How do I remeber that from a year ago? Well, because if it wasn't for the two non-nitrox divers, we would have had a much longer 2nd and 3rd dive. I wasn't close to being OOA, but I was on the edge of my non-deco time.

That day is one of the reasons I did my nitrox cert this past May. DH did his cert just before our December trip. We're doing our first liveaboard trip next week where we'll be able to do up to 4-5 dives on at least three of the five diving days of the trip. The dives will be mostly shallow (75ft and less) I'm very glad we'll be able to do most of these dives on nitrox. It should make for a more enjoyable and safer trip.

 

[underachiever]

Hey Michigan Diver.
When in April are you headed down? This will be our first trip to Cozumel also and we are still kinda new at this also. We will be there 4/20-4/29

 

[DandyDon]

May I introduce myself?

I did such a trip a year ago or so. We went south, around the most southerly point and back up (El Islolte) diving three tanks on our way back around, finishing at Palancar Gardens. SIs were done on the boat, as I recall. According to my log, 1st dive was 21% to 105 ft. for 50 minutes, second dive after a 1 hr. 10 minute SI was to 62 feet for 66 minutes on 32% nitrox and 3rd dive was to 57 feet for 85 minutes on 32% nitors after a 2 hr. 15 minutes SI. Scubawife, please correct if I have this wrong as you were on the same boat.

While I agree this isn't a "normal" profile, it's not beyond the pale with ops that offer big tanks (which include nitrox tanks) or unlimited bottom time. In fact, more like the norm.

Sounds like some great dive days, and yeah - I can certainly see Nitrox being indicated for at least one tank a day, with two a day being a prudent upgrade. If it had been only 2 dives a day like the first 2, I probly wouldn't bother - but again, still a prudent upgrade, and I guess some would do both on Nitrox with good reason - even tho I wouldn't?

MichiganDiver I don't want to hijack this thread with answers to your questions here. If you don't find them reading the forum, how about starting a new thread? But this is often discussed here, so you may not need to. Did you enter your stay on the Cozumel calendar above this forum...?

 

[Christi]

I'm confused by those of you who say that nitrox is only customarily used on thesecond dive here.

Dives in the 60 to 80 foot range derive the most benefit from nitrox, if extending your NDL's is your objective.

Those of you who are nitrox certified know (or should know) that you can safely do a 100 to 110 foot dive on 32%. With a few exceptions, this depth is not usually exceeded on the first dive here...no need for it unless you're jsut trying to be macho...or unless you are doing a dive such as Devil's Throat which takes you slightly beyond MOD for 32%, or Maracaibo deep which is WELL beyond MOD for 32%.

I routinely have divers who dive nitrox for both tanks (32 and 36 or 32 for both dives). Of course it's a personal decision and everyone has their own reasons for diving nitrox. As long as you understand the dive planning and theories behind it, and can safely dive with enriched air (and are certified for it of course), then I don't see any disadvantage other than the additional costs...which again is a personal decision.

 

[CozzieDive Laura]

Christi, I totally agree with your point.