15. Mounting Depth Finder Transducers ...

By Tom Neale, 11/4/2004

Mounting Depth Finder Transducers Inside the Hull

I’ve very seldom mounted a depth finder transducer through the hull on a fiberglass boat. Instead, I devise some way of having it read through the hull. Although manufacturers’ instructions warn of reduced performance should you do this, it can be done successfully on most solid hull fiberglass boats.

Reduced performance from in-hull mounting (and other causes) is most likely to occur in faster boats because of the greater degree of turbulence under the hull. The reduced performance may be that the unit will be less likely to recognize fish, if that’s the type you’re using, or it may mean that the depth finder won’t see the bottom as far down. If the reduced performance means that it can only read down to 400 feet instead of 500 feet, the reduction is probably a fair trade off for the benefits of in-hull mounting.

There are several benefits to in-hull mounting. Not insignificant is the fact that the transducer is likely to survive longer if it is safe inside the hull. If it does go bad, it’s very easy to replace. Another benefit is that, should you find under running conditions that turbulence interferes with the transducer, it’s much easier to move it than would be the case if you’d drilled a hole.

Some transducers are plug and play mounted with a special through hull fitting, allowing for removal and replacement while the boat is still in the water. These are great. They save money and make it easy to replace a bad transducer. But I still prefer to mount the transducer inside. If you have a failure while you’re out, it may not be convenient to pull out a bad transducer, with a hole in your hull for even a brief moment, and insert the new one. A depth finder is so important that, whether you’re using a plug and play feature or an in-hull mounting, it’s wise to have a second transducer ready to go, with wire run in place.

For more of Tom’s Tips for installing a transducer water box inside the hull go to www.tomneale.com

Copyright 2004-2005 Tom Neale