Originally Posted by Jizm
Just remember though that some of the older GPS units take for ever to acquire the satelites!
Even if it's particularly slow, if you switch it on before you launch it'll know where it is before you start the engine. Ihave an old Garmin 12 & it usually knows where it is within 30s of switching on, always <1 min.
If you want really cheap and don't mind scrificing a bit of accuracy, could you get a pitot transom mount dial type? I've seen them go 2nd hand for under a tenner.