A diving watch should be much more than just waterproof to a certain depth. It should be able to log your dives, be able to be read under water, measure depth and duration of dive, measure water temperature and of course have a nice long warranty.
Here is my ideal diving watch, a Citizen JV0030-19F Diving Watch.
It does all that and more. The price tag is just under $500 but for what it does it is well worth the price. You can find it at the same site that sells bulova watches.
If you have a diver in the family it would make a great gift.