Everyone usually comes up with a different answer Malc but most would agree that the best of the small boats units are Garmin, 100, 160, 240 according to your budget. They also have a series made particularly for salt water use ( I think they're called 'blue')My unit is the 240, it's utterly reliable gives a very clear picture, the basic model has surface temperature, there is a transducer which gives speed as well and it's completely weatherproof. No contest.