I am looking to buy a GPS unit so that I can troll more effectively, in particular I think I need a unit that will tell me my boat speed.The last one I used on a friends boat would not read under 2 mph. Is there a unit that will read down to 1 mile an hour or less? thank you for your help,

Dwight, In order for a gps unit to tell speed you must be moving, I'am sure you know that. Both my units will not read under 1 mph I think thats as low as they will read. You mite get a reading of .5 once in a while, but not to often.