Just what is better, a transom mount transducer of a through hull?
Most modern transducers can "shoot through the hull", which eliminates the problems of both a transom mount—which is far more vulnerable to damage; and the problems with a through-hull—which can leak and requires drilling through the hull.
The only real issue is if you have a cored hull or undiscovered voids in the hull layup. However, you can test for this by moving the transducer around the bottom of the boat until you find a spot where it works properly by "test-mounting" it using a ziploc bag filled with water.
My preferred method of mounting a "shoot-through-the hull" transducer is to epoxy or glass in a piece of 4" PVC schedule 40 pipe with a clean out cap on it...and then mount the transducer to the clean out cap. This way the transducer is easily removable for maintenance or replacement yet sturdily enough mounted that it can't be knocked free by accident. Fill the PVC pipe with mineral oil and you're good to go.
Adrift, after a short trial of trying thru the hull, I used one of my old holes for my new fishfinder/depthsounder/chartmapper. Does having a fishfinder make any difference? Are there better ones or worse ones for our solid hulled fiberglassed beasts?
Newt-we've had 3 fishfinder depth soumders-
all set up to shoot through the hull. Our first was a Humminbird dual beam and it was great Secomd (different boat) was a single beam and it always had problems. Even had it reworked by Humminbird to no avail. Replaced that with a Lowrance finder, transducer glued down in same spot and it is great. just find a place using a baggy of water or a big gob of Vaseline , then glue it down.
Thanks Charlie, I will use the baggy of water trick next time.