how many dives is too much ?

[Charlie99]

A bit surprising no one has specifically commented on the short duration of Surface Interval #3.

That was the first thing to jump out at me when looking at the OP, particularly since the average depth was 18m, which means he didn't spend much time shallow.

When doing a series of dives like this, I find it particularly important to do a at least 2 or 3 stops on the way up. Instead of spending just 1 minute at 1/2 of max depth, I find it useful to start adding more time. For example, 2 minutes at 1/2 of the way to the surface, then another 2 or 3 minutes around 30 or 35 feet, and 3 or 4 minutes in the 20'-10' range, sliding upward slowly during the stop.

Pay attention to your body. If you feel great, vigorous, energetic and ready to do another dive after the whole series, then you've done a good job of controlling your profile and ascent. If you are tired and dragging, that's your body telling you that you've pushed beyond where you should.

 

[Charlie99]

on comp i never went into NDT closest i got was once and had 3 min , felt perfectly fine

Deco isn't very precise. 3 minutes of NDT left or a couple minutes into deco is pretty much the same level of loading: heavily loaded.

The no-deco/deco transition on computers is sharply defined as the computers change modes. With your body, though, it a very very fuzzy transition and a few minutes one way or the other is really the same for all practical purposes.

 

[ajduplessis]

I'm surprised nobody has mentioned a very reasonable way to make this kind of diving safer, which is to take a Nitrox class. Nitrox will reduce the nitrogen loading for a given profile, keeping you further from your no-deco limits. If you are doing multiple dives in a day, Nitrox is a very smart thing to do..

No Nitrox available at this site.

 

[bowlofpetunias]

People have been talking a fair bit about depth but bottom time is also a vital factor. Great to talk about 4 or 5 dives but how long are they?

 

[DevonDiver]

People have been talking a fair bit about depth but bottom time is also a vital factor. Great to talk about 4 or 5 dives but how long are they?

More importantly, is the issue of dive profiles. The ave depths indicate that the dives were not square profile, but also did not spend a lot of time at shallow depth.... so maybe not a 'nice' curve, with a gradual, constant ascent and proportionally large amount of time spent in the shallows.

 

[bowlofpetunias]

All aspects of course are important not just number of dives in the day but their Depth, Profile, Bottom time (which IMHO means how long and at what depth), Ascent Rates, type of gas used and work loads.

All of these factors must be considered to decide how conservative or agressive the day or days of diving are.

 

[batman diver]

In my opinion, your dive planning could have been a good bit more thorough than just "don't go into deco" or "stay more than 10 minutes from deco."

You were wearing a dive computer, and at the very least, you could have used it for your dive planning before each dive. It will take into account your theoretical N2 load based on your previous dives and your surface interval up to the time you enter the planning mode, and it will tell you what your NDLs are for the depth you plan to dive to.

i did use the planner on my computer thats how we decided when we were out for enough time , etc ....should have mentioned that sorry , we were using a cresi archimedes 2 ( known to be a tad too conservative and a Tusa Zen )

thanks fr the note on the book i am def going to look into that , and with regards to nitrox it is difficult as its not available at the venue witch is rather silly considering , i also have not done nitrox , ( thats next on the list when money comes in again ) - student .

with regards to feeling tired i felt pretty energetic and was using that as a gauge before doing each dive , after the last dive i was pretty tired if i am honest , but with the deeper ones i felt fine. ( am o correct in assuming lethargy is very minimal for of excessive nitrogen build up )

thanks to every one for the valuable input , so just to clarify , if i went again i could do all that again ? , but i would increase the sit times to 2 hours , and maybe grab a nap between one of the dives ? i think the biggest issue was the sit times hey ?

one last this sorry , comp has auto altitude adjustment , and i follow it on assent as it works out ideal assent rate ...

 

[batman diver]

dives were "square ish" they got the lower ave depth because i take a while to descend , usually 2 min and then up and down the object i would be at , witch is around 3 - 4 meteres

 

[Quero]

thanks to every one for the valuable input , so just to clarify , if i went again i could do all that again ? , but i would increase the sit times to 2 hours , and maybe grab a nap between one of the dives ? i think the biggest issue was the sit times hey?

I was glad to read that you actually did do more planning than you had indicated earlier. :thumbs_up:

I think that as long as you are comfortable with your dive plan and follow it, you can do it again. When doing multiple deep dives, though, longer surface intervals are important. If your main objective is to swim around the submerged objects, then perhaps you don't need to do the fourth dive at the shallower depth--especially so soon after your third deep dive, and particularly if the motivation for doing it was to offgas.

It sounds like you're having fun with your dives and are learning how to manage them.

 

[Charlie99]

with regards to feeling tired i felt pretty energetic and was using that as a gauge before doing each dive , after the last dive i was pretty tired if i am honest , but with the deeper ones i felt fine. ( am o correct in assuming lethargy is very minimal for of excessive nitrogen build up )

Just as the NDL/mandatory deco transition is very vague, fuzzy and broad, so also is the transition between bent and not bent.

Decompression (including decompression from a dive within NDL) is an insult to the body. The key is to control and minimize that insult.

Each person is different, and your body's response will also vary from day to day. The best way I can describe the effect of decompression on my body is to compare it to wind and weather exposure. There is one sort of tiredness and fatigue that I associate with heavy exertion .... lots of running or exercise. There is another sort of blah feeling from just being exposed to the elements for long periods ..... lots of sun, lots a strong wind. After many hours, the accumulated insults to the body take their toll. Bad profiles/bad ascents/pushing the limits gives me that 2nd sort of tiredness.

It's my firm belief that the "you feel better with nitrox" controversy has its basis in people having subclinical DCS (the fancy term for the postdive blahs I described above) when they do a series of dives on air, and not having subclinical DCS when doing the same series of dives on nitrox.

Try to keep in mind the general sort of feeling you had after that last dive. If indeed it really was a result of a dive series/profile that was too aggressive, in the future you can use your body's feedback to set your own personal limits.