The Catalina 36 V berth is laid out with one large V shaped cushion and a separate insert to fill in the Vee area attached to an upholstered board that fits/rests perfectly onto the trim of the berth. Invariably, just as we become fast asleep, the insert falls to the cabin sole. Since our plan is to sleep on the v-berth to enjoy the nice custom mattress who came with the boat, it’s time to fix it!
The solution was to put some velcro tape:
I had to staple the velcro tape against the insert (update: so far after 5 months it still hold perfectly to the v-berth).