Air strategy for 4-5 tank dive days?

[sharky60]

I haven't dove like that since I was in the Navy. 2 tanks are more than enough for me nowadays.

 

[Streydog]

It is hard for me not to want to do afternoon dives when we are heading back, the weather if perfect and you see dive boats heading back out to the reefs.

What computer are you using? One day I did 4 dives, 32% on the first dive and 36% on the remaining. I hit deco toward the end of #4 on my Suunto while my Geo still had 30 minutes of NDL.

 

[Scuba_88]

I think the Suunto's are pretty conservative from what I remember. I'm using a Shearwater Perdix.

 

[horn34]

So we keep getting conflicting advice and hopefully those here who dive with 3P can chime in. We just did the Spring Lake DAC/PADI course and dove with a DM who spent the last 3 months in Cozumel. He said he didn't think alternating air/36 was a good idea for Cozumel due to the depth on many of the dives, since our MOD with 36 is pretty shallow. He said he dove with air 100%.

So we're trying to choose between alternating air/32, or air/36 or one 32/36 tank out of 4. Or even all air. Thoughts?

 

[scubadada]

Dive with 32%, the MOD at 1.4 is 111 feet, 132 feet at 1.6.

 

[AdivingBel]

If you're diving with 3P you'll want nitrox of some sort on most (all) of your dives unless you are generally gas limited (as opposed to NDL limited). You'll have the opportunity to dive your tank with 3P and on air you'll be throwing away a lot of bottom time. As far as the risk of exceeding MOD, everyone does their own risk assessment. Having dived several times in Coz with 3P, diving 32 on the deeper (first) dives and 36 on the shallower (2nd) dives I've not had any issues. Some invert that choosing to lessen their initial nitrogen load while some dive 36 or 32 for all dives. To each their own, but to dive air only with this op seems a waste (but still fun ). All IMHO, YMMV.

 

[Streydog]

I have only dove with 3P's twice so I couldn't say this is the norm but here are the stats from the 2 days. These were all on air.
Site Max Depth Average Depth Dive time
Day 1
P Horseshoe 76 52 51 Minutes
Cedral 65 44 63
Day 2
Bricks 94 54 57
Cedral 78 46 61

Towards the end of the last dive my Suunto had me down to 1 minute of NDL.

How are you on air? I have no idea what the typical afternoon dives are but I would assume they would be similar to Cedral.
At the minimum I would budget for 2 EAN tanks and day, out of 4 dives, and play it by ear during the trip.

 

[scubafanatic]

4 to 5 dives daily, go with EAN 32 on all dives, keep it simple, consistent......flipping all over increases the odds of forgetting to program your computer correctly. My experiences are EAN 36 is very uncommon, EAN 32 is pretty much the Nitrox 'standard'.

 

[scubadada]

I dive 36 percent frequently in SE Florida and frequently change between tanks, not a big deal

 

[scubafanatic]

I dive 36 percent frequently in SE Florida and frequently change between tanks, not a big deal

I think we're talking about Cozumel, not SE Florida, just sayin'.