New divers and computers

[Amberjack]

Thanks, everyone, for your comments and advice - particularly Charlie 99 - some of this stuff is kind of like deciphering a foreign language, but I'm working on it!

Anyway, it's all been very useful. I just ordered a computer (after reading lots of threads for recommendations) but I vow in front of all you good folks to use it responsibly!

Plus, whoo hoo - my first dive gear purchase!

 

[TDvanNiekerk]

When we logged our last two cert dives, we were slightly off the tables, but well within the limits of the instructor’s computer.

I am not sure what you mean with being "slightly off the tables". If you meant that you did not stick to your dive plan and went deeper or stayed longer than planned, then that is still fine. You simply recalc your pressure gruop after the dive, based on the actual dive, as usual.

However if you would have gone into a decompression dive based on the tables, it is less than ideal. Off course you are well advised by others to buy a dive computer but you may also want to look at this from a different perspective.

Before the dive you should know the planned depth and duration of the dive. Even if it is a training dive. The instructor or DM briefing should include that. Then look at your tables for that depth and see what your maximum safe time is for that depth.

Even if you dont plan to stay the maximum time, now you know your limit. If the dive site has deeper depths, then also look at the safe depths for the deeper depths. If you make a note of these you will know the limits of your dive profile.

It is a simple but effective way of avoiding mistakes. For example: You are diving in Fort Lauderdale (my home base ) on a wreck that is 100ft deep. Looking at the tables you will see your NDL is 20 minutes. Just remember 20 minutes and you know your safe limit. Even if you have enough air and your instructor is busy teaching, when you approach 20 minutes, you can indicate to your instructor that you are going to end the dive and ascend (the thumbs up sign).

You will see many divers with computers just jump into the water and only check their computers and air, without having an idea before the dive as to how long they can stay at depth. Almost all computers allow you to plan the dive and get the same result as the tables, check your NDL BEFORE the dive and remember that.

If your computer breaks down while you dive, you cal always end the dive safely because you remember your NDL. Even if you have to check the dive duration on your buddy's timer - hope you dont have to.

I suppose I am trying to stress that you should base your dive on a planned duration and not on your dive computer's remaining NDL.

 

[sewcopp]

Amberjack
Your computer is your first purchase? That's a step but you still rent your suit, mask, fins, snorkel, regs. tank,....? I've done things the other way around. The only thing I don't own for diving yet is the computer. Interesting.

 

[Amberjack]

Amberjack
Your computer is your first purchase? That's a step but you still rent your suit, mask, fins, snorkel, regs. tank,....?

No, not exactly. I've had mask, fins and snorkel that I use for snorkelling for years, so I wasn't thinking of them as a dive purchase. I will probably need to get new fins that are better for diving - I've got a pair of full-foot fins at the moment that are only OK - but I figured that with everything else, I can rent until I figure out what I like best. I understand that's hard to do with computers.

As for suit, which sounds like it's frequently the next step, I want to take a dry suit course and do some local diving first, before I decide if I want to invest in a dry suit. I'm not sure what thickness to get for a wet suit, because I'm still not sure what kind of diving I'll be doing the most of.

The rest will come - regs, BC, etc. eventually, but I really need to do more diving first. And I can't imagine I'd ever think it was worthwhile to buy my own tanks! But, you never know.

 

[Crawl79]

My first major purchase was a computer, and I would tell all my friends to get this first also. I luckily bought a computer a day before a liveaboard trip to the Flower Gardens in the Gulf of Mexico. I was at the LDS renting my other gear as usual and they recommended it. I would have been the only person onboard without a computer and would have been limited to the amount of dives I could have enjoyed while everyone else would have been diving and having fun. Now I am already upgrading to a more sophisticated computer but that computer definetly made a great trip even better and I will never regret making this purchase from my LDS (others I have). And now I have a spare computer for myself and for buddies to borrow until they buy there own.

 

[Charlie99]

I've done things the other way around. The only thing I don't own for diving yet is the computer. Interesting.

The type of diving you are doing makes a huge difference in how useful a computer would be. If you are doing dives that are fairly close to square profile than a computer doesn't have very much advantage over tables. If you are doing decompression dives where you need to hold to a schedule in order to ensure that you have the gas(es) needed to the required decompression, then computers don't help you much.

Where computers are most useful are in multilevel dives such as a reef or wall dive with interesting stuff to look at both deep and shallow, particularly when you are diving the site for the first time and you have only a vague, general plan for the depths on the dive.

 

[nauidiver2004]

I cant believe your diving with full foot fins? Have you been in Lake Ontario or the Niagara River with them? HOLY COW! I am in Buffalo and dive Lake Erie all summer, It can still be a bit chilly at depth, I would freeze if I didn't have something on my feet.

 

[Amberjack]

I can explain the full foot fins - I've never done any local diving! They have been used exclusively 'down south' - will need to trade up for chilly Ontario waters for sure! But as far as I can gather, people need to use different fins for their dry suit and wet suit boots. Again, I'm not sure how much cold water diving I'm going to do yet, so I don't want to buy anything until I've given it a try.

 

[sewcopp]

I do most of my diving locally. Not necessarily square profile but mostly shore dives and there is usually lots of us at the site. I've found the computer guys don't mind the few extra minutes of SI (at the barbeque, drinking soup or just chewing the fat) to wait for us table dudes. It makes them a little safer and we all get the 2 or three dives in that we've planned for the day, and leave at about the same time.

That being said. Yes I own a wet suit, dry suit, 2 sets of fins, 2 tanks (my husband has the other 2 but if one of us is not diving the other has the use of 4), MSF, reg.s, BCD (I got a good deal on these as a package when I HAD to go weight integrated). So now I need a computer. Especially since I'm doing my SDI/TDI Dive master and Assistant instructor.

I'm thinking abut a Suunto. It's a brand I've known for years for land based equipment and from what I've read it has algoritms that can be changed to be more conservative. Any of you guys dive with a Suunto of any description or do you mainly use the American made gear?

Sue

 

[StSomewhere]

Suunto can be changed to be more conservative, but its already one of the most conservative "out of the box"...