Not the cheapest option but look at boxousa. I've used their roll up bags of tools in different situations and they are a space saver and the quality is pretty good! Lots of choices. Their "boat" bag is linked below.
Boat Roll | 82-Piece Boat Tool Roll and Dry Bag
Introducing the BoatRoll 82-Piece Boat Tool Roll and Dry Bag by BoxoUSA, the ultimate toolkit designed for recreational and performance boating enthusiasts. Crafted with precision, this kit includes a curated selection of the most commonly used metric and SAE tools for boat maintenance and...
boxousa.com