I've had the Velocitek S-10 model for two years now and it's been great. It gives speed and VMG on a big display and is housed in a bullet proof case. It is especially handy on a cat since seemingly minor adjustments can reep 2 knots of boat speed. Learned some interesting things the first day I had it. Went out xmas eve and came home to lay the tracks down on Google Earth and GPS Action Replay, both are free downloads. If I was good at this computer crap I could attach the tracks but I'm not so I can't. Anyway here's the link. Great piece of kit. Ed

http://www.velocitek.us/