Tips for Buying a Dive Computer
Do you dive with Nitrox?
If there's even the slightest chance of you using nitrox, or wanting to in the future, then it makes sense to buy a dive computer that supports nitrox diving. Generally, these dive computers only cost a little more, and buying one that can match your pace as you advance through your training and diving experiences will prove cheaper in the long run.
Do you want to show your cylinder contents?
Air-integrated dive computers monitor how much gas you have remaining during a dive, and your breathing rate. They will tell you how much time you have left at a given depth (whether that's limited by your remaining air, or your dive time). The dive computer can also work out, if you're breathing slow, that you've absorbed less nitrogen and therefore can permit you to stay down longer. Longer dives - what's not to love?
Wrist or Console?
Generally this is a matter of preference. Bear in mind that if you choose a console computer and don't plan on taking your regs on your next dive trip, you'll either need to hire and use a dive computer you might be unfamiliar with, or take the dive computer console off of your regs and put it on the hire regs. Some people go for the 'big watch' style dive computers and wear them every day. Our preference, especially for technical and cave diving, is for a large, easy to read wrist mounted dive computer.
Time-to-fly is the time you must wait between your last dive and ascending to altitude. Most dive computers display the amount of time remaining until residual nitrogen levels drop to the point where the computer considers a subsequent dive to be the same as a non-repetitive dive. This time may be described as a time-to-fly. However, even after considerable study, flying after diving recommendations remain controversial and continue to evolve. Decompression sickness statistics from Divers Alert Network (DAN) make it very clear that no current decompression theory and computer algorithm is able to account for all the complexities of decompression introduced by flying after diving. Instead, we encourage you to follow the May 2002 Flying After Diving Workshop recommendations published by DAN:
- For a single no-stop-required dive, a minimum preflight surface interval of at least 12 hours is suggested.
- For multiple dives in a single day, or multiple days of diving, a minimum preflight surface interval of at least 18 hours is suggested.
- Wait substantially longer (i.e., 24 to 36 hours) if you have done any decompression-stop-required diving.