This shows the wasted space under a seat in the dinette area. I had already removed the table and added extra cushions to creat a U shapped seating area.

The result holds 2 toolboxes plus a bunch of spare parts. The old seat is the lid for the new storage area

I measured for the rough shape and built the L shaped addition at home in the garage. All trim pieces were cut on a table saw out of solid stock.

The plywood is butt jointed, glued and nailed after pre-drilling so as not to stress the ply. The nails are for alignment as much as strength. A triangular wedge piece was fitted to the inside of the joint and   an L shaped trim piece on the outside. These were all glued and clamped using a construction square to line it all up. Top U shaped trim pieced were then mitered and glued in place.

A trip to the boat was needed to mark for the final cuts to the bottom.

 The original seat support needed to be shortened by 3/8” to allow the plywood to slide behind the mast support beam. This was difficult to do because I did not want to remove it. Care was taken so as to not mark up the bulkhead wall.

After the final cuts were made, I fabricated the pine anchoring supports for the inside. These are 1” square and were cut out of some clear 2x4’s. The one along the curved edge required marking a 1x3 and cutting with a saber saw. All pieces were glued and clamped in place.

The finished part was sprayed with multiple coats of an indoor semi gloss poly.

The finished part was then screwed down to the liner, the sole and the mast support beam.

The seat was reused by adding a board to the back to align it. To remove it one just lifts at the rear.

I put an old throwable seat cushion in the bottom to make up the difference in the depth. The tool boxes don’t move around that way.

Comment on gluing: I tested several glues to see what would hold the best and I was not satisfied with the polyurethane glues. I finally settled on my old favorite; Elmer’s Carpenter’s Wood Glue. It is water resistant and held better than all others on teak. I would be interested in other opinions on this. An alternative would be to use epoxy which I also have had good luck with. I cleaned the teak with thinner prior to gluing to remove as much of the natural oil as possible.

Actually the triangular wedge piece is not teak. It is made from a piece of Honduras mahogany that came off of Rivendell. Small trivia point. But it is strong and glues better than teak. And I had sentimental reasons for using it.