NavList:

I started out using an expensive self-winding wrist watch.  But it wasn't accurate enough, and combined with my questionable sight taking techniques on a rolly ocean, my fixes were poor (poor enough to miss the island of Nuku Hiva by 30Nm!).  I switched to a digital watch and checked it every so often  against my HF radio's time ticks (can't really remember the frequency) .  I got better and better with more miles under the keel!