I am looking for some sort of device , That will give me the true speed of my boat, I have GPS on board and I have tried the wheel on the back of the boat. But they are just not true speed. When it comes to trolling speeds. IS there something else on the market.
Maybe something you could tow behind the boat . Speed range I am looking for is ( 0 to 5 ) MPH. I just want to be accurate in this range for trolling. Maybe something I could hook on the cannon ball of one of my downriggers.
I leave this in your good hands folk's.