Welcome to ScubaBoard, the world's largest scuba diving community. Registration is not required to read the forums, but we encourage you to join. Joining has its benefits and enables you to participate in the discussions.
Benefits of registering include
Dive computers do not make dives safer. Unless the user actually understands the info they're seeing and makes use of it. Many new divers actually take computers and use them to make their dives more dangerous and increase their risk of a deco problem. New computer users will fly their computers right up to the limits in the false belief that they are being safe. Tables for newer divers are much safer. The scenario of seeing something 15 or 20 feet below your PLANNED depth for a properly trained, disciplined diver is going to be observed from that 15 or 20 feet away or they will have PLANNED for such a contingency and have a contingency plan on a slate or in their wetnotes, Having such backup plans is common practice for tech divers. It is not hard, it takes no more time than any good plan, and is just good practice.
You can also use tables for multilevel dives as easily as any electronic gizmo once shown how and you don't have to worry about getting them wet, dropping them in the water, even setting a tank down on them. You can even run them over with your car and they will still work.
Dive computers do not make dives safer. Unless the user actually understands the info they're seeing and makes use of it. ... The scenario of seeing something 15 or 20 feet below your PLANNED depth for a properly trained, disciplined diver is going to be observed from that 15 or 20 feet away or they will have PLANNED for such a contingency and have a contingency plan on a slate or in their wetnotes,
Other than running out of air, I think a primary hazard to new divers is too fast of an ascent rate. A dive computer makes it simple to maintain a safe ascent rate. If it gets mad at you, it beeps, blinks and should give a good warning of an accelerated ascent rate. This capability alone provides a significant safety advantage, particularly to new divers.
I can only speak for myself, but as a "mature" diver I need something I can actually read underwater! The dive watches I've seen generally suffer from small print. Even many dive computers are difficult to read for me, especially since they cram so much into such a small space. Those still blessed with 20/20 vision may be fine with a dive watch.
I would recommend a watch and depth gauge over a computer. Not just to save money but to reduce your dependency on something that can quit on you if the battery fails. The other problem with computers is while they can give you more bottom time it is at the expense of reducing your safety margins. To avoid carrying tables with me I used permanent ink to write the no decompression limits on the arm of my wet suit