Installing GPS/Depth Finder
 

Hey guys, Just bought a GPS/Depth finder and trying to figure out the best way to install it. I have a place on the dash to mount it, but the depth finder sensor part needs to be mounted on the transom, any ideas on the best place to mount it and where to put the hole to run the line. The line that runs from my speedometer pickup to the speedo runs through the outdrive somehow, can i follow that line?

Might want to consider getting a thru-hull transducer rather than having it hanging off the back of the boat. Don't have to drill holes that way. I assume you are using it simply to tell how deep the water is and not for fishing, viewing underwater structure, etc? The thru-hull ones aren't as sensitive, but as mentioned, if all you need it for is depth- it'll work fine and be a lot cleaner install. The one on my fountain is mounted near the middle of the boat in the bilge under the cuddy stairs. Otherwise, you will have to drill a new hole in the transom above the water line (1/2" or bigger) to clear the connector that goes into the back of the unit (it can't be disconnected or simply cut and spliced ).

There are pros and cons to both transom mount and thru hull transducers. For the transom mount style, advantages are a bit more flexibility on location and aiming and generally more accurate. Disadvantages include being easier to knock off, possibilities of getting water into the transom if mounted incorrectly and even some water spray while in motion. The keys to mounting these are proper location and sealing off all holes drilled in the transom. Use a good marine grade sealer like Life Caulk and don’t scrimp on the application. I’d locate the hole for where the transducer wire actually penetrates the transom as high up as possible.

Thru hull transducers lead to a much cleaner looking installation – if done correctly. The problem here is correct location / installation. First – particularly with a cored hull – you need to find a location where it will actually read. With the boat in the water (preferably at a known water depth), take a plastic shopping bag and put about a cup of water in it. Next, plop your transducer into the bag and twist the top so no water leaks out. Now, with the depth sounder on and the transducer plugged in, move that bag around the inside of the hull and check the depth. In most cases you’ll find that the transducer will not read correctly in all locations due to air entrapped on the layup. When you find a spot where everything works, mark it.

Next, when you go to adhere the transducer to the hull, make sure you very carefully spread the provided epoxy and be very careful when mixing and spreading it not to entrap any air bubbles. Press the transducer firmly in place and secure it with tape until it cures.

Hope that helps!

Tom

If i could avoid having to mount it on the transom that would be great. I'm not really sure where would be a good place to mount it on the hull. My engine compartment is pretty tight so getting to the bottom of the hull is difficult, and inside the cuddy, the only access to the bottom of the hull is through a small drain hole that is a little bigger than a half dollar. any other thoughts

Make sure transducer has no aeration passing under it from hull protrusions,strakes,steps, etc. Takes clean water with no air voids to get a good read whether thru hull or transom.

You do not ever want to use a drain hole to run wires through a hull.

With all due respect, it sounds like you're new enough at this game to really need a professional to install the transducer for you. Speaking as one who's worked in the business for over 25 years, you simply cannot imagine the damage caused by well meaning folks doing things like this themselves. And explaining it on-line generally won't be good enough due to all of the variables involved.

Good luck and be careful.