Originally Posted by pedcab
My advice would br for you to go for a unit bought from a reputable electronic supplies store. Even the cheapest units sold there are often much better than more expensive ones sold at the discount bins of DIY stores etc...
I'd suggest getting one from a car (auto) store, the ranges are more likely to be useful on a boat. Flukes are great, I have two at home, but there is no way I'd take one on the boat.