I was under the sink fitting an electric water pump switch and I was shocked to find the 1" square vertical softwood corner supports for the ply shelf and front section has woodworm. I did not see any dust to indicate that the woodworm is active but on poking at the square section in parts it just crumbled away. Although it is a GRP boat there are lots of wooden sections e.g. bulkheads, sink joinery, longitudinal stiffeners on the hull and lots of wooden formers under the steps on both sides. Apart from the balsa cored cockpit floor.

Having said it is not active at home we had a wooden salad bowl for 30 years and it had a few holes in the bottom when I bought it new and just thought that was from borers in the tree it came from. I then found the woodworm was active 30 years later evidenced by the little circles of dust around some new holes in the base! So were the larvae dormant all that time or had new flying insects lain eggs there using old holes?

I am going to have to remove the afflicted wood, 4 pieces in total and treat the area-not something you expect in a GRP boat.