Oy….
Several sources, including Rochester Institute of Technology and several manufacturers of foam based products would disagree that polyethylene (foam) pipe insulation does not have the compressive strength of “pool noodles”. In fact foam insulation is denser (and has greater compressive strength) than PN’s.
If you really need ‘battleship grey” noodles. These will certainly help roll your “250 lb” boat down hill.
Here’s a few links to put you to sleep while you finish your scotch tonight:
https://peer.asee.org/fifteen-plus-y...s-and-more.pdf
https://alcotplastics.com/save-money...0outer%20layer.
https://aeroflexusa.com/rubber-versu...ich-is-better/
Sleep tight.