MPH tach???

[hondavxr]

I don't know if this question should be here, but here it goes. My boat that I just bought does not come with a MPH gauge and I was wodering if any of you guys know how to rig one up on a boat? I know how to work on cars all day long but this marine thing is all new to me. Give me any advices on gauge brands and wiring. Thanks for any replies in advance. FM is the greatest.

[waskawood]

I would save my money and buy a GPS. The guages I have seen are not very accurate. You can add a wheel to some of the graph locators but they aren't as accurate as a gps either. If you don't want a full size gps look at the hand helds they are a little cheaper.

[Northlander]

Ditto

[hondavxr]

Will the hand held gps's read instant mph? I fish a lot on the Croix and I always gun my rig. I am just worry that I might be going over the speed limit. I need something to a least give me a rough estimate so the sheriff's won't be the ones telling me my mph when they are giving me a ticket. I guess I will look into a gps.

[fishingdad]

I agree with the GPS. I know my garmin handheld updates every second and is right on with my eagle chartplotter on the boat. Smart thinking cuz' they are not afraid to write a ticket on the st. croix. good luck

[Valv]

Standard speedometer works with a pickup tube on back of boat or from motor, water enters this tube all the way to gauge, speed is measured by pressure of water on gauge.

The faster, the more pressure, the more speed is marked.....very inaccurate.

GPS= 12 satellites watching over you all the times, measure exact speed at any moment, best accuracy.

I was out on lake Michigan with high waves, and it mesured the difference of speed from going up a wave and going down a wave...that tells you how accurate they are.

Also low speed is not pickrd up by speedometer

Go GPS....