There is one serious problem with installing only a gps aided knot meter on a boat...You never know what the boat is doing through the water. The GPS directed systems only tell you your boat speed over the ground so you can not compare the speed of the boat through the water, thus you really don't know the affect of the current on the boat....

Dan I have a comnav which is now nexus marine, system on the boat; boat speed, depth, and compass. I really like the system as it has every feature I could ever imagine using, and it is simple to install and operate. The nexus system is easily expandable if you wanted a wind instrument, which like tack tick is wireless, so no wires in the mast. There are a lot of good reliable systems out there, even the over the counter raymarine sold at West Marine is a good option. But I can tell you this I wouldn't sail a boat on SF bay without a actual in the water knotmeter.

Tom

:: Hi Dan,
::
:: We have been using the Velocitek Prostart. It works
:: quite well and updates fairly quickly. The features are
:: similar to the KVH unit.
::
:: I believe it is also class legal as it is all integrated
:: to itself as for the GPS.
::
:: Don
:: :: Does anyone have a recommendation for a knotmeter? We've
:: :: been using a Speedmate for a long time. It's a good
:: :: unit, but is incredibly unreliable (maybe that's why
:: :: they don't make them anymore). I tried the entry level
:: :: TackTick (T035), but found that it reacted too slowly
:: :: and there is no way to adjust the damping. What else is
:: :: good out there?
:: ::
:: :: Thanks
:: ::
:: :: Dan