Boat Speedometer Options?

Question

I'm sure this is a common problem for people who dock their boat in salt water, and it's very frustrating!

My speedometer on my boat uses a typical Pitot on the bottom of the transom, that measures water speed by sending pressure through the small tube to the speedometer guage. It rarely works once the boat has been in the water for a while, due to barnacle growth and other marine sludge.

I want to know if I have any other options in a speedometer setting. (I already have a GPS that also gives speed, but I want my guage to work too, plus I don't always use my GPS - I don't really need it for where I go).

Why don't they sell a Pitot that resists barnacle growth, and other sludge? I've even tried painting it with antifouling paint in previous years, and that didn't work either. I've used new Pitots over and over with no luck every year, they fail. There's got to be a better system for a Guage Speedometer!

Answer 1

Just get a GPS Speedo to fit in your original speedo mounting hole, you can buy a speedometer that acuatually uses a small GPS receiver to figure the speed instead of a pitot tube, they are a fair amount more expensive but you'll never have another plugged tube again :)

http://www.livorsi.com/catalog/gps.htm

Answer 2

you need a gaffrig speedometer and a lift for your boat. Don't just let it sit in saltwater. That's terrible for your boat.

Answer 3

None I know of.

I just keep cleaning them.

Answer 4

Your "speedometer" does not measure speed made good, but speed through the water.  In my view pitot tubes are useless and are unreliable for the exactly the problems you encountered.  Get rid of it and use your GPS.  Best thing to do is to practice prudent coastal or celestrial navigation.

Answer 5

There is a speed wheel that logs speed and attaches to your transom or thru hull.  Get one that interfaces with your speedometer.

Answer 6

no not really the are designed for fresh water and even then they still plug up.  I would use the gps it is your best bet

Answer 7

Welcome to the world of boating>Those are not reliable as current can change the speed by 3 mph or kts>Best use your GPS as that reads speed over ground true reading>& never needs cleaning>