Vin once bubbled...
I swear by my computer- but always set the bezel on my watch. I am on the market - what do you dive with? Pulsar- Citzens- Rolex?
Consider an automatic mechanical dive watch by Citizen or Seiko. They also make the pseudo-electronic ones that recharge via body motion. Under $200 but made to last a lifetime.
Rolex and Omega as watches are fine for diving beyond 500' regularly.
However, to date only Citizen makes the combination watch & depth-gauge, charged by solar cells. Thus, you have a watch-bottom timer that so far, never needs to have its battery replaced and serves as a main or backup bottom timer. The gauge reads only to 130', but that's good enough for dives to 230 for 30min were the deco ceiling is about 130'. Thus, if you had a bottom timer crap out at depth, you can safely deco out.
While you can get cheap good dive watches from Casio and others, all of them need to have batteries replaced.
It can be done cheaply by yourself or a watch store for under $20, but opening the case requires a new o-ring, which is nearly impossible to find. Thus, a watch rated to 300m may no longer be depth rated. Shipping the watch to the factory for recertification results in a higher periodic cost in battery repairs, about $50+.
Finally, don't use the watch straps the watch comes with, rather use the safety straps made for diving, about $5, a velcro version sold by ISC, or an Australian nylon one with stainless steel rings for $12. If the 50c mounting pin pulls loose, your expensive watch will fall off into some abyss. These diving straps secure each pin to the strap, so you need to loose both pins together to loose the watch, a very very rare condition.
Don't bungee a watch strap either, the cord is too thick for the pins and will snap them.