[sailnaway]

Garmin makes a three in one Speed ,Depth ,Temp. You can plug it into several of the insterment displays they have including diffrent models of the Garmin GPS. The transducer comes with a long thru hull it looks like it may be four inches. That would let you use a fairing block to bed the transducer in a straight up and down manner for best results. The faring blocks can be bought in fiberglass or I have made my own in a plastic throw away bucket using layers of matt and cloth resin lay up at an angle let kick off and pop it out of the bucket. epoxie that to the inside and the material becomes part of the hull strong as heck.