How to plan an intensive multi-day diving schedule.

[kolmogorov]

Hi, I plan to schedule multiple days of diving, 4+ tank a day, and considering combinations such as a night dive on day N, followed by a deep morning dive and easy afternoon dive on day N+1. According to the dive tables, after about 10 hours surface time, I am back to the lowest pressure group. This does not tell me much. How could I do a more precise calculation to factor in the accumulated nitrogen. Better tables? Specialized software? I took quite a few courses and I do not remember any specific guidelines that would prevent me from doing, say, daily 4-tank dives for 100 days in a row... surely, there must exist limitations known to the diving science. I would be grateful for any pointers... we are talking about recreational dives in warm water, mostly in the 60-100 foot range.

 

[Doc]

There is comparatively very little in the literature in regards to multiple dives, certainly the regimen you are describing.

Remember- the tables originally came from "square profile" work dives. Plonk to one depth, do a job, ascend. Multi-level diving is, by comparison, still a pure guess. Add to that the differences in individual bodies.

Consider the usage of the concocted phrase, "undeserved hit".

If you are really serious about this, I would suggest that you stay a lot shallower than you were thinking and maintain a very unaggressive dive profile. You do not mention nitrox and Oxygen issues, that puzzles me.

I regularly do 5x day at Cocoview Roatan Honduras including a night dive. My profiles are very shallow, usually in the 45' average- I have learned that there is more interesting stuff to see by staying shallower. I do this on air and have yet to violate a very conservative computer and I have suffered no ill effects (and I am not an 18yo Navy diver by any stretch).

After 100 days of that kind of schedule, I would be equally worried about ear issues.

 

[DivemasterDennis]

First of all, invest in a quality computer for the trip, and for all trips. Learn to use it, and use it. Next, draw your mind back to your open water training ( and AOW if you took it) where you learned to calculate dive profiles. You should have learned how to calculate pressure groups for multi-level dives. You can "make up" a dive day, and see how much surface interval you need. Also remember that with multiple dives over multiple days you want to be conservative in your planning. Here's a real simple example:
Dive 1, 8 am 60 feet for 44 minutes.
1 hour surface interval
Dive 2, 10 am, 60 feet for 30 minutes
2 1/2 hour lunch break/surface interval
Dive 3, 1:15, 60 feet for 40 minutes
siesta and surface interval until 6:30
Dive 4, to 50 feet, for 55 minutes
dinner and bed time, until day 2.

These bottom times are about as far and you can go conservatively. You can increase bottom time with longer intervals. Increased depth will result in shorter bottom times. Practice calculating NDL,s but modify your plan as each dive presents an actual profile. I like to do calculations on all my dives as multi-level dives.
Also, monitor your computer regularly. It won't help you if you don't look at it. Dive planning is every bit important a skill as is buoyancy control. Like all skills, practice makes perfect. Have a fun and safe trip.
DivemasterDennis

 

[RTee]

You can also simulate the profiles you have in mind on Dive Planner software such as Suunto using air, nitrox or a combination of the two and see if it might be achievable or not....from an algorythm perspective.

 

[ianr33]

Nitrox.

 

[DiveNav]

Hi, I plan to schedule multiple days of diving, .......... How could I do a more precise calculation to factor in the accumulated nitrogen. ......... Specialized software?........

You can try with divePAL; with the Tech version you can enter an infinite serie of multi-level dive profiles and analyze them in detail.

Keep in mind that any dive planning software gives you ONLY a "detailed ESTIMATE"

+1 on using Nitrox.

​

Alberto (aka eDiver)

 

[kwinter]

Rebreather

 

[RonFrank]

I have done very aggressive profiles over a week. I only did that after doing many weeks of non aggressive profiles. IOW's I did not jump into the deep end rater I did a gradual build up. However there are very few places I dive where I am tempted to dive deep daily. Coz is one.

If you do not have a history of pushing NDL's then doing so from the get go is a bad idea. Theoretically NP but one never knows.

 

[Damselfish]

Unclear - are you talking about a typical week or 2 dive trip and just threw the 100 days thing out there as a sort of example, or are you really talking about 100 days or something unusual in some way, like some NOAA related thing?

People do week or 2 warm water dive trips all the time with 4+/- dives a day. If you're talking about a typical trip like that, I suggest a computer and Nitrox for the actual trip. If you get one with a simulation mode that does this sort of thing you can play around with that, or use some of the software that's available if you want to experiment and see how it goes. But practically speaking, you'll find it's just not that hard to make this work. And realize that lots of other things other than your accumulated Nitrogen (or Oxygen) will affect what you actually do - are you tired, how your ears are doing, the dive sites, the weather, boat schedules if you're boat diving, your buddy, air consumption, where the cool critters happen to show up that day, whatever. And on a longer trip many people do take a break in the middle and/or dive less aggressively, even if they're ok in theory.

Be careful about the word precise - calculating multilevel dives with a computer or software is certainly much more precise than treating multilevel dives as square table dives. But none of this is all that precise.