Garmin 72
You can't find a better boating GPS for 150 bucks than the Garmin 72. It has coastal navigation aids (not very handy though), backlit screen, speed in MPH and Knots, 500 waypoints, WAAS, 8 mgs of memory (not much but good to store a few trips) and a very handy trip computer. Some of the really helpful features are a tide chart (this book itself costs 20 bucks) and a anchor alarm- if your sleeping on the hook and your anchor lets go, an alarm will go off to let you know. Very good stuff for 150 small ones.