Before rushing into subbing the skirting for extruded PVC strip, however, it pays to consider its SG and the likely affect on both buoyancy and trim. Happily there is a wonderful resource in the shape of the European Council of Vinyl Manufacturers. As a member myself, I can tell you that they are based in Brussels where their annual jamboree and beer-fest is well attended by dozens of PVC devotees dressed only in orange polymers.
Turning to our screens, however, we can see that unlike laminated extrusions of a mixed density ~ hard on the outside and soft in the middle, like the curate's egg ~ they are exclusively heavier than water.
I fear I am going to have to build a static flotation tank in the garage, which is how the clinical obsession with boats that might fly often presents.
