I have Perfect Pass with the paddlewheel, as I ride on a tidal river so there's always a current and it's always changing. My remaining speedometer is just about worthless as the pitot gets clogged so frequently as to make it unusable. I've been thinking it would be nice to replace the Airguide with a GPS speedometer so I can have speed over water at low speed from the PP and GPS for higher speed... and also use the GPS to calibrate the PP at slack tide. Wouldn't be a true speed over water but the Airguide is worthless with a plugged pitot anyhow.

I see there are GPS conversions for the Airguide and parts available to restore them (http://www.classicboatwork.com/class...e/agr/agr.html). Anyone tried this? I was gonna order it until I saw that it is not accurately calibrated to the dial. It will be off either a couple MPH at low speed or a couple MPH at high speed. To me this seems to defeat the purpose of the GPS, and I'd rather not spend all that money to have a speedo that is not accurate at all speeds. Of course it would be better than a plugged pitot and non-functional speedo all the time, and I'm mostly a purist so prefer to keep things as original as possible while improving functionality. My boat is a tool first and foremost, and a classic ski boat second.

The other option I see is Livorsi Ski GPS (http://www.livorsi.com/catalog/gps_ski.html). It would not be a perfect match or as nice as the original Airguides, but then again the PP gauge doesn't exactly look at home in an '80s ski boat either.

Anyone know of other GPS speedometer options appropriate for our boats? Most of what I see is high speed speedometers without large easy to read graduations for typical water sports speeds. I don't want or need an 80+ MPH speedometer. 50 MPH is fine, 60 MPH would be nice but not necessary. Thoughts?