A blog about SCAMP (Small Craft Advisor Magazine Project) boats. Covering the build, sailing the boat and the scamp community that has formed around this little portly boat.

Monday, May 18, 2015

Lowrance chartplotter mount

I bought a Lowrance Elite 4 chart plotter on sale at West Marine.
I needed a mount for it that I could remove so that the plotter won't get stolen when she's on the trailer. I decided I could make a mount like Simeon has on B3 for Noddy, but on B4.
If I move if aft, I'm a bit worried that the sun will wash it out sometimes, but it should work fine.

I started with some doubled up scrap I had left over from a sole hatch.
Mount plate
I found some circles I had from cutting out hatches that fit the curve of B4 very well.
circle fits well in the B4 cutout.
A little trimming of that circle left me with a pretty good approximation of the curve.
I didn't get any pictures, but I cut a small triangle piece to fill in the lower gap.

I 1/8" roundovered the edges and got it ready to epoxy.

Then I mounted those pieces on the backerboard and put a layer of fiberglass to thicken it out so it was a bit wider than the 6mm bulkhead.
epoxy wet out

Then I glued on the front piece.

Glued up. Note the tape wrapped piece of 6mm plywood to keep separation.

Here it is dry-fit in place.
It needed sanding and a bit of a fillet on top. I also drilled a hole all the way through both pieces and the bulkhead to accommodate a 3/16" quick release pin so that it stays put.
amidships side. You can see the pin hole through the dual layers at left.

athwart side
This week, I'll prime this and paint it the color of the interior.

I've also drilled some holes for the wiring. Unfortunately, I don't have any idea where I can mount the HDI skimmer transducer. I could mount it on the transom, but I don't want to run those wires. I'll test it first and see if it will shoot through the hull. Supposedly you can't sonar through a wooden hull.


  1. A boy and his toys. Great thinking

  2. So, instead of just removing the unit head from the removable base, you've made a removable base for the removable base? ;)

    Looks good. Please make sure to report how trying to shoot through the hull works.

  3. I wanted to be able to remove the mount entirely and not have the ugly black mount sticking out of the bulkhead.

    I don't know if shooting through the wood hull will even work. Many people recommend putting the transponder in a bag of water and setting it in the hull. This simulates embedding it in epoxy stuck to the hull.

  4. Jeff - I too understand that you can't shoot through the wood hull, but one thought I had was that you could drill a hole through the hull and fill it with epoxy (and I think I'd put fiberglass both sides), and then you could mount your transducer inside and shoot through that. -- Dave

  5. I thought about using a router to route all the way through just the wood, leaving the outer fiberglass shell. I could then fill that with epoxy and set the transducer in there. At this point the transducer is not essential and I'll worry about it later.

    Frankly, I suspect that shooting through the hull will work well enough for my purposes. I'll try it and find out.