Installing Through The Hull Components


I recently changed the GPS receiver location on my boat, from my dash to where it really should be, outside the helm area and in the open.  The reasons are obvious, a clear line to the sky, I guess I just didn't want to drill another hole in my boat!  However, after losing the signal countless times and having to "reset" the sounder,  I finally bit the big one and drilled that hole.  I will admit that an upcoming salmon trip out on the west coast also gave me some incentive for the hole, if there's any place you want a clear signal on your GPS chart its out on the chuck, in fog!

Drilling the hole isn't exactly brain surgery but there are a few things that should be done in order to make the installation not only good looking but long lasting, performance wise.  The hole surgery wouldn't be so bad if the GPS (Lowrance) manufacturers would make a different connection for joining the receiver unit to the head.  They make a big bloody connector that requires you to drill an inch hole just so you can pass the 3\16" cable through it!

Anyways, once you've decided on the right spot for your receiver or any other component that you may have to have pass through the hull somewhere, here's just a couple of precautions I take to prevent problems down the road.  The picture below was what the end product looked like once installed on the boat, however, I forgot to do one simple thing and that tape and rubber hose beside the unit show what I forgot.  No matter what you do when you pass a wire or line through the hull, especially aluminum, you are going to have rough edges, filing it or not!

So, all I do is to take a piece of rubber hose that will fit snugly around the GPS wire and wrap it with that.  Just slice the rubber tube lengthways and then slide it over the wire where it will pass through the hull.  Some black electrical tape will secure it in place so it doesn't` slide down and your good to go!  Along with the rubber hose trick I also paint the drilled edges of the hole, to seal it against any sort of corrosion.  If you don't have paint then I'm sure a good quality silicone would work just as well.  The base for the GPS unit is attached to the hull via two screws, both of which I Loc Tite in place and ensure the screws are also fully coated.  These GPS units can be either installed with or without the base,  I chose with the base so I can take the top section off when doing longer trips.  There's nothing worse than a rock coming up and busting that GPS receiver, they aren't cheap!  The top section then just ``screws`` onto the attached base, and is easily removed.  Also, for any of you that do salt water trips its nice to have that top unit removed for washing out the area with fresh water once you get home.  Nothing worse than have salt water sitting somewhere that it can't escape and next thing you know you've got corrosion happening!

Here's a great thread ( that explains exactly what crevice corrosion is on aluminum boats, how it can be caused and how it can be prevented.  As per the information on that thread, crevice corrosion just doesn't happen from salt water, it can happen anywhere water can collect and sit, as long as it has no exposure to the air.  That's why its so important to make sure the areas that you do drill through or cut through are coated/painted with something but still have some exposure to the air.