Timing of Dives

[Pulmcc]

A bigger difference than the depth is the time consumed loading on and off the boat, and the trip to the dive site. 2 boat trips a day doesn't leave much time for relaxing on the beach. That maters more to some than others.


That is the normal schedule for most shops in Cozumel. The morning boat won't be getting back to the dock until almost 1 pm. The afternoon one won't be getting back till after 5 pm.

Thanks for that info. I will check with them to see what the expected interval is between the last morning dive and the first afternoon dive.

 

[Pulmcc]

Thank you to everyone for their suggestions. Thoughts on this revised plan?

Day 1: two deep dives, morning or afternoon
Day 2: two deep dives, morning or afternoon
Day 3: 4 rec dives, 2 morning, 2 afternoon
Day 4: possible 2 rec dives in the morning (return flight on day 5 is around noon the following day)

 

[Dan G]

Why would you need to dive air on the deepest dives?

I suppose the instructor can keep the third dive shallower than 111' if using 32% and satisfy the requirements of the course, but I would imagine they may want to have a deeper MOD so there is the option to go deeper than just 10' deeper than Dive 2. In Cozumel, I think you can get 28% if you really want it, but it's at a premium and takes advance notice from what I understand. I have never seen anyone with anything other than 32% or 36% there. The other option is to exceed 1.4 pO2, but I do not envision an instructor doing that with students in an OW specialty course, nor would I recommend it.

 

[inquis]

Day 1: two deep dives, morning or afternoon

The boat operators typically do a shallower second dive that wouldn't be appropriate for your certification. I suggest you discuss things with your instructor and/or operator -- they may be able to start the second dive near a slope/wall so that you can do something deeper while others can do the longer/shallower dive.

 

[tursiops]

We will be going to Cozumel in a few weeks and will be able to dive 4 days. We have to complete our SSI Deep Diving Specialty Diving certification so will need to do 4 deep dives. If we do two of those dives each day on consecutive days but also want to do 2 fun dives each day (so total 8 dives over 2 days), does it matter which dives we do in the morning vs afternoon? I vaguely recall reading that if you want to do 4 dives in a day, you do the deep dives in the morning and then the shallower dives in the afternoon. Is that correct? Also, would diving with Nitrox on the non-deep dives be a good idea?

I'm confused. The SSI Deep Diving Speicalty only has three dives:

• Dive 1: 18 to 30 meters

• Dive 2: 24 to 30 meters

• Dive 3: 30 to 40 meters

Dives 1 and 2 can easily be done on Nitrox 32. Dive 3 could be done on Nitrox 28.
Dive 3 requires an instructor-student ratio of 1:4 max, so is not likely to be part of a normal Cozumel group boat dive.
Just for good nitrogen management and fatigue, doing the deeper dives in the morning and the shallower in the afternoon is a good idea.

 

[lowwall]

I would not want to do that many dives in that short of period. It would seem like work rather than a vacation. Space out your dives, so you are always refreshed and eager for you next dive.

Everybody is different. I love doing multiple dives in a day. I've been on liveaboards that offered 5 dives a day and I've done every one of them.

 

[L13]

I suppose the instructor can keep the third dive shallower than 111' if using 32% and satisfy the requirements of the course, but I would imagine they may want to have a deeper MOD so there is the option to go deeper than just 10' deeper than Dive 2. In Cozumel, I think you can get 28% if you really want it, but it's at a premium and takes advance notice from what I understand. I have never seen anyone with anything other than 32% or 36% there. The other option is to exceed 1.4 pO2, but I do not envision an instructor doing that with students in an OW specialty course, nor would I recommend it.

32% is easy to get, 36% is much less common. Haven't seen anything else available (but haven't really looked).

But yes, doing the 3rd deep dive on air probably is a good idea.

 

[Kendall Raine]

32% is easy to get, 36% is much less common. Haven't seen anything else available (but haven't really looked).

But yes, doing the 3rd deep dive on air probably is a good idea.

FYI Aldora fills 36% for the repets. Others may, as well.

This is a course, so all the deep dives are likely short MOD bounce (tag the MOD) dives. You can confirm with instructor. 30-40 m MOD is a PO2 of 1.28-1.60. CNS toxicity is a curvilinear dosage function. Time at MOD likely to be a few minutes, if that, right? Tox really not an issue on 32% at MOD given short time there.

I don't know if PO2 > 1.4 is allowed in a recreational course (probably not), but bigger question is what is someone with 0-24 doing in a course like this in the first place.

 

[scubadada]

...I don't know if PO2 > 1.4 is allowed in a recreational course (probably not)...

I doubt you are allowed to exceed the MOD in a recreational course.

My son and I did PADI Deep Diver in Grand Cayman in 2004. Our 130 foot dive was on air.

 

[Pbdiver84]

FYI Aldora fills 36% for the repets. Others may, as well.

This is a course, so all the deep dives are likely short MOD bounce (tag the MOD) dives. You can confirm with instructor. 30-40 m MOD is a PO2 of 1.28-1.60. CNS toxicity is a curvilinear dosage function. Time at MOD likely to be a few minutes, if that, right? Tox really not an issue on 32% at MOD given short time there.

I don't know if PO2 > 1.4 is allowed in a recreational course (probably not), but bigger question is what is someone with 0-24 doing in a course like this in the first place.

Aldora does 1st dive 32%, 2nd dive 36%.

Memo has confirmed they do their own blending, and will do a weak nitrox like 28% if requested for deep diving. You have to push it with the front desk a little… nice guys, but not super creative.