tables vs computer

[kittyfish]

I recently completed my OW cert, and just came back from a long weekend diving trip (my 1st ocean dive). IT WAS GREAT!!!!!

Anyway, I rented a computer for the trip, and it was a tremendous help, especially since it is hard to keep up with your log book and other things on a crowded boat. Well, when I finally started filling in all the information I found that my numbers put me in the red on the dive tables, even though the computer read " no dec time".

Every dive plan that the DM gave was - [60 ft for 20 min then 40 ft for 25 min], and we had at least 1-2.5 hr surface interval. According to the computer, the deepest dive I had was actually 75ft. No doubt the DM was signaling me to come up a little more.

I belive what is on the computer, but do computers often conflict with the dive tables, and should I continue to follow the info on the computer, and not worry about the tables?

 

[MNScuba]

Dive the tables... use your computer as a backup.

 

[Starfish]

I think everyone here would tell you to dive the tables and use the computer as a back-up.

It sounds like you dove within conservative limits on the tables (above 60 feet and moving up in incriments or steps over time), so I would be surprised if you were into deco times. Double check your calculations.

 

[devilfish]

Computers calculate based on multilevel profile giving credit for shallower depth calculating every three seconds or so resulting in longer underwater time. Dive tables are based on square profile, meaning the whole dive time is based on deepest portion of the dive. To extend dive time use a computer, however dive tables will result in shorter dive time. Therefore diving with a computer results in a more aggressive dive.

 

[ckharlan66]

Yea what he said.

Chad

 

[Tavi]

Learn to dive Tables .....yes.

Dive the tables........ not always.

When I'm on vacation I dive my computer. Thats one of the reasons I bought it, repetetive multilevel dives. It gives me more bottom time, and I think it does it safely as Suunto is known as being one of the more conservative computers.

Learn the tables because........ if I'm at 90fsw and the computer says 40 min No deco time
I know there is something drasticaly wrong

When I get into training for deeper dives I will dive tables or computer generated tables, and use the computer in guage mode or as back-up.
For vacation and most recreational diving I trust my computer. I Do tables occasionally so I don't forget how.
"use it or lose it"

 

[Uncle Pug]

Well...
Ya know I hate to jump into this...
But...
Computers will rot your brain.

Use both for now... and see if you can discern why the two give different results.

Keep track (at 5 minute intervals) of your depth and SPG reading. See if you can write these figures down after the dive before checking your computer's log function. Yes this takes thinking and some will argue that it takes away from the carefree abandon of simply diving and being one with the fish. Fish are fairly stupid. But at least they are equipped to *breath* water and have unlimited bottom time. You need to exercise your brain and become smart because you can't and you don't. After time this will actually become much easier and you will be able to mentally keep track of your time/depth profile during the dive as well as your air consumption.

The computer between your ears is being programmed.

 

[art.chick]

After AOW, I bought a computer & got real lazy. Yes, on a crowded boat, you have a lot on your mind, mostly, keeping your gear together for the next dive while grabbing a snack. But in a class I took last summer, we had a long lecture on tables by a guy who created one! I did not realize that they varied, that they were based upon studies of how human tissue absorbs & lets go of nitrogen, and that the studies had different data! Now I enjoy the fun of owning several different tables (NAUI, US NAvy, & HUGI). Of course I only use one per weekend of diving. Tables (and computers) only MINIMIZE risk, they don't erradicate it. If you are minimizing risk with consistency to the best of your ability IMHO you are a pretty responsible diver. Computers are good for many things, esp to let you know how fast u r ascending, but I don;t know any instructors who consider them replacements for tables.

 

[Tavi]

Originally posted by art.chick
I don;t know any instructors who consider them replacements for tables.

I heard one instructor say that a computer is like working and updating a table every 20 seconds.

 

[Kat]

I have no experience with dive computers. Always use the tables. Is the computer something I should look into or should I just go with what I know? I have often thought that the calculations are not truly accurate on the tables because if your diving 35ft. the whole time then spend 5 min at 50ft. you calculate the dive at 50ft. I would have more bottom time w/ the computer but would I be able to take advantage of it? As it seems to me that the DM's on vacation send everyone up at the same time.