Poor grad student in need of regulator advice

[willgr1]

does your school have a dive locker on campus? with a field in marine research I would assume the university would be equipped to supply it's faculty and graduate students with the equipment they need to do research.

My graduate school has a dive locker full of dive rite gear available for use when conducting research. I would think with the amount of dive you plan to do borrowing gear from a dive locker would be the more logical approach.

 

[halocline]

A computer would be both expensive and probably unnecessary when we almost never go deep enough to require a safety stop.

I would not be so sure about that. If you do some reading on basic decompression theory (you are a grad student, so you can read, hehe) you'll find that with enough time even shallow dives will load you up with N2. The slower tissue compartments usually control shallower dives, and although they take a long time to saturate, they also take a long time to off gas.

It's probably a very good idea to spend some time at 10-15 ft at the end of every dive just as a habit. The main reason I brought up the wrist computer is that most divers find it much more convenient to have depth/time info on their wrists, where you can see it all the time, while gas pressure you only need to check a couple of times during the dive. It would not surprise me if you could get a plain SPG, simple wrist computer (or bottom timer) and a wrist mount compass for about the same price as the console.

 

[ZzzKing]

He's probably going to be air limited on the 20-40' dives rather than NDL limited unless he's diving doubles or has an incredible SAC rate. The US Navy says 200 minutes (3 hours and 20 minutes) at 40'. The occasional 100' dive is easily planned and executed with tables.

So if he knows he's gonna be doing 1 dive a day, he should probably wait on a computer until he can fit it in the budget or until he needs it to execute the dives he needs to do.

Good idea to check if the university has a dive locker, though.

 

[hudson]

The only real improvement to the MK2/190 setup would be a MK2/G250V.

 

[LockeOak]

He's probably going to be air limited on the 20-40' dives rather than NDL limited unless he's diving doubles or has an incredible SAC rate. The US Navy says 200 minutes (3 hours and 20 minutes) at 40'. The occasional 100' dive is easily planned and executed with tables.

So if he knows he's gonna be doing 1 dive a day, he should probably wait on a computer until he can fit it in the budget or until he needs it to execute the dives he needs to do.

Good idea to check if the university has a dive locker, though.

Yeah, for about half of our dives 15' is the max depth of the dive. The other half max out at 35-40'. We do a max of two tanks a day. To give you an idea on how shallow we work, I've been getting by on snorkel for some of our sites for a while.

As for a dive locker, I wish. Funding is extremely short for everything, my lab was able to scrape together money for mask, fins, boots and snorkel. Everything else (including certification for PADI, CPR, first aid, etc.) is self-financed.

 

[vixtor]

Maybe a MK11/S555 would be a good choice for you if it is cheap enough. Better than MK2/R_whatever because it is balanced.

 

[halocline]

I wouldn't worry too much about the balanced/unbalanced bit. The MK2 is a perfectly acceptable performer, with a 15 PSI or so IP drop over the supply range that you won't notice until 500PSI. One nice thing is that they seem to be extremely tolerant of not being serviced often. There are no dynamic o-rings exposed to HP air, that's a biggie for long term reliability.

Getting back to the computer and N2 loading, sure he's going to be air limited on individual dives, but if you're doing several dives a day, 30-40 feet will definitely load you up and as I mentioned before, the off gassing on those slow compartments takes a long time.

But, I think the OP has since commented that he's only doing two dives/day, presumably on AL80s or other fairly small tanks, and that much of the dive is at 15-20ft. That's almost certainly not worth using a computer for.