Affordable Dive Computers

[inquis]

The idea that these things are so absolutely gospel and necessary is a bit funny to this old school diver.

You do realize those same sort of estimates, algorithm choices, modelling assumptions, rounded resolution display, etc. pervade the table guidance, right?

Overstaying your bottom time through lack of awareness -- regardless of whether a computer or table provided that time -- is what is so frowned upon.

 

[Landau]

No one has suggested the most simple setup yet. Purchase a good mid price dive computer that you can afford. Then buy a nice cheap Casio dive watch and keep a set of dive tables in your BCD pocket.

And how do I use those tables without knowing how deep my dive was? A depth gauge is needed as well, that might increase the total price to be very close to a cheap computer.

 

[wetb4igetinthewater]

I would rather not buy two dive computers that are each $1 grand or more but two computers that are about $500 as I am not doing any tech diving.

Shearwater Peregrine

 

[gmerick]

Multiple trips, (resort, liveaboard, and cruise ship). I now carry 2 computers and pack a spare. Primary (and newest) is Shearwater Perdix AI, backup is Aqualung i200 on a retractor, spare is Aqualung i300 watch style.
Agravation: Bubble and Buhlman do not match. In planning my end of dive, I have to check both, and respect the most conservative. On violation, the Aqualung will lock out for a day, the Perdix will just complain. My next comuter will have Buhlman like the Shearwater. Prior to each dive, I look at the dive planner on the computers to note predicted bottom time at planned depth.
Bottom line: Dive trips are paid for ahead of time, with no refunds if I skip dives. A computer failure will cost me a whole lot more in lost vacation dollars than any budget computer. The Perdix AI with two transmitters costs less than any Caribbean trip. For almost any other gear failure, regs, bc, mask, the next dive can most likely be saved by rent, borrow, or spare. Computer failure will always impact a full days diving with either risk acceptance, risk mitigation, or outright missed dives.

 

[tridacna]

And how do I use those tables without knowing how deep my dive was? A depth gauge is needed as well, that might increase the total price to be very close to a cheap computer.

@DogDiver included a cheap dive computer which provides a depth reading.

 

[bradlw]

I was not taught tables in my SDI OW class. They require computers from the very beginning. I laugh at the OW classes which pretend computers don’t exist, force people to learn tables, and then students never use tables again. Why not just teach the way they’ll dive from the beginning? The only table I use is the nitrox one to determine mod/PPO2 for recreational dives. Why do math if you don’t have to? (I hate math)

a few reasons off the top of my head.....
so folks can have a reality check about this stuff. To not be so hypnotized by the black magic in fear of multilevel diving and all the unknowns without those little numbers displayed. To understand that if your computer dies mid dive, it's not a reason to panic or for emergency accent NOW.
to develop habits of keeping a mental note of what the computer was telling them 2 minutes ago when they last look so that they can reliably fill in the blanks and reasonably finish or end the dive using depth and time estimates.

That said, I don't disagree with your sentiment that we need to be careful against doing things without reason....lor just becasue that's the way it's always been done. I never understood the need for multiple open water training dives for my Nitrox certification back in 1995. If memory serves it was 2 dives. Still seems like a huge bunch of silly to me.

 

[bradlw]

I've never heard of a liveaboard doing more than five dives a day, and every one that I've ever been on requires the use of a dive computer. I will say that after multiple trips doing every dive while watching the Searwater tissue loading graphs, having one fail mid-trip wouldn't worry me all that much. Except for the slowest compartments with their minimal gas load, all compartments are clear every morning.

maybe not common, I don't know. Surely dependent upon depths and other variables

I've only done the one liveaboard and that was I think called "The Ultimate Getaway" back in to 1990's put of Ft Myers down to the Dry Tortugas. They opened the pool many times a day and into the night. It was diver's choice if they wanted to jump in our not. A lot of divers skipped several. I was young and a diving animal back then... I remember that I dove every time the pool was opened except one. Per my logbook the most in one day was 8. I needed a vacation to rest after that vacation.

What you say about observing the computer after many dives and the "compartments" being clear.....
That I think is similar to what I came to realize back in the day after many charter boat dives in SE Florida doing the typical 30ft -130ft 2-tank dives using alumimum 80's.... sure it's good to monitor, and you should follow the displayed limits...BUT with the built in surface intervals and planning that the boats do...deep dives first, shallow second, doing the safety stops, following common sense rules about gas management, etc.... almost everyone will run out of air before getting too far astray. So maybe just maybe dive boats don't steer the dive plan to the degree they used to and let folks dive their own computers + maybe computers and the industry in general is a bit more conservative than we used to be... but to me back in those days the best thing about more folks diving computers back then was that it gave a nice little indication of ascent rates and warned if too fast.

 

[Landau]

@DogDiver included a cheap dive computer which provides a depth reading.

But I thought the watch and dive tables were for backup in case the cheap computer failed. For backup I'd need a depth gauge too.

 

[tridacna]

But I thought the watch and dive tables were for backup in case the cheap computer failed. For backup I'd need a depth gauge too.

You better keep a spare set of dive tables too. Never know.

 

[wetb4igetinthewater]

So question for anyone. What percentage of the divers out there prefer to use dive tables over a computer?

Now I don't have any data to back this up, but my gut feeling is that the people who like to use tables and have that as a backup plan to their dive computers is a marginal percentage of the divers out there. So small, it almost isn't worth talking about as a practical option.