Modern dive computers are complex devices with so many functions and features that sorting them all out can get downright dizzying. When shopping for that perfect DC we find that, rather than first looking at a dive computer’s features, it’s best to first take a look at yourself as a diver.
What’s more important to you: maximizing your bottom time or maintaining a reasonable safety cushion?
How you answer will determine whether you should be looking for a dive computer with a liberal algorithm or a conservative algorithm. The algorithms used in all dive computers are designed to help divers avoid decompression sickness (DCS), and while they all have remarkable safety records, at the same point on the same dive they can provide dramatically different NDLs. Consequently, a younger, very fit, somewhat aggressive diver might prefer a more liberal algorithm that maximizes his bottom time, while an older, perhaps not quite as fit diver might want to go more conservative to maximize his safety cushion.
Remember, all dive computers can be made more conservative by programming in safety factors or by just backing off on the tissue loading bar graph. But only in rare cases can a computer be made more liberal. We’ve come across many divers who didn’t learn this until it was too late. Having to return to the surface 10 to 15 minutes sooner than your dive buddies who are diving more liberal computers isn’t the time to discover that the computer you bought isn’t suited to your diving style.