I've been a fan of Suunto sailing watches for years now and I personally own a Suunto Mariner (Click here for more info)
. Despite it's large size, it has great features for racing and other navigational features (like a barometer!) that really make it a handy tool even when chartering.
Sometime in early 2006, Suunto is improving their M9 Sailing Wristop Computer Watch w/ Barometer, Compass, & GPS
with the new "M9i" model. It looks pretty damn cool. It has a USB port to connect with your laptop. It's actually smarter than you. (maybe...)

While these may seem a little extravagant, I can honestly say there is nothing like having your own GPS with you while chartering. By inputing some key coordinates before you leave, it gives you a navigation system you trust and can take much anxiety out of navigating in new waters.
Has anyone used one of the older M9s? I'm curious to hear how well they work.