For most, understanding how to plan repetitive dives using a dive table was the most torturous part of learning to dive. Removing this pain from an otherwise pleasurable activity is usually benefit enough for most people to invest in this ubiquitous scuba gadget. If you need more justification, here’s ten more reasons.
Dive Computers © Janne8086
- Ease of use
Versus working out your dive profile using tables, recording it on a slate and monitoring your plan underwater using your depth gauge and watch; using a dive computer is easy. It tracks your surface interval and adjusts your no-decompression limit for repetitive dives accordingly. All you need to do is remember to put it on your wrist and correctly interpret what it is telling you. Yes, you need to read the manual!
While they are not completely idiot proof, they do eliminate mistakes that can be made reading dive tables, working out pressure groups and carrying forward theoretical nitrogen loads for repetitive dives.
- More Time
Because dive computers track your profile accurately, they will give you more time underwater than a dive planned using a table. A table can only plan a square profile dive and assumes you spend all of your dive at a given depth. The table can’t offer any credit for ascending to a shallower depth. It is possible to plan a multilevel profile using table based calculators. This method will give you more bottom time but there are limitations, and it would still not be as generous as a dive computer.
Diving using a computer offers the flexibility of altering your plan on the fly. Within reason, dropping down an extra couple of meters to photograph a pygmy seahorse is not an issue.
- Ascents and stops
Dive computers make tracking your ascent speed, and safety stop much easier than a depth gauge and watch.
Computers can be set so that they will audibly alert you at a given depth or a given dive time. You can see where either of these functions could be useful.
- Logging and tracking
Many computers allow you to download your dive to your PC where you can scrutinize it and create a dive log. This digital version enables you to add photos and notes and can replace your tatty water-stained paper version.
- Air Integration
You can integrate your air pressure into you dive computer readings. Some see this as a benefit and some as an unnecessary doohicky. Computers built into consoles will provide the diver with an accurate remaining time based on their air consumption and current depth. For a wrist mounted computer to give the same information, a transmitter is attached to the regulator’s first stage, but the connection between the two is far from failsafe.
- Other gases
Nitrox is getting close to being standard on scuba diving vacations. Rather than using yet another set of tables, most computers allow you to set the level of oxygen that you are using and will calculate your no decompression limit accordingly.
- Save Money
Increasingly dive operators are making computer use mandatory. If you don’t have one, then you will need to hire one, and this cost is supplemental to the standard gear hire package. Expect to pay GBP5-10 per day. A perfectly adequate dive computer can be purchased for around GBP150, cheaper if you catch a sale or exercise bargaining skills at a dive show.