My guess is the first thing one has to do is define "going to sea". If it means a coastal trip from one anchorage to another then any old watch will do and as some posts say, even no watch in some cases is good.
But if you're going to sea from one continent to another then a decent watch is essential. Having wizzbang atomic clock reporting in to your GPS is so useless for this because it is when your GPS stops working that you will hopefully be taking a sight with your sextant and you will need accurate time which your GPS can obviously no longer provide.
I have a Seiko Sportura multi time zone which has been accurate to the second since I first set it in March of 2007. I guess when it needs a new battery then it'll have to be reset but up to now it's been perfect. You can see the one I have here:
Sportura - World Timer Chronograph | SEIKO WATCH CORPORATION