Can't speak to your specific boat but, Unless the configuration is strangely different from mine:
1 Use poster board (probably 3 sheets taped together) or cardboard from a furniture store discard and map out the dimensions of the runners that should still be in place, along with the fore and aft length. Cut template into a triangle shape.
2. Dry fit template into V berth opening between the port/starboard cushions.
3 Lay template on a piece of 1/2 inch plywood. Cut to fit.
4 Dry fit plywood in V berth.
5 Sand and shape plywood as necessary.
6 Seal plywood with epoxy resin or varnish.
7. Put plywood into V berth and measure height from top of plywood to the top edge of adjacent cushions.
8. Buy foam to match thickness and firmness. Shape foam to fit the plywood.
9. Make cover to fit assembly in fabric of your choice with a vinyl bottom and a zipper in side edge or bottom panel.
OR, take those dimensions, current v berth cushions, including foam, to an upholstery shop like
U S Yacht Cushions in St. Petersburg, Florida
(Or call them (727) 322-5352)
and let them do it! They have the original patterns.
