These are both foul release coatings Seaspeed being the one I'm leaning towards, mainly because it is hard and I can run it up on the beach without damage, the Intersleek, I'm not sure but I don't think so. Also the Seaspeed seems less fussy about the prep.
Is surface finish all there is to it ?
Because Seaspeed has it all over the Intersleek.
Seaspeed VX10 has a quoted surface finish
of <10 microns average
Intersleek 900 has a quoted surface finish of around 70 microns
The intersleek product did very well in a structured test here - https://www.tandfonline.com/doi/full...kTPUFg7jyEm7w&
Unfortunately Seaspeed were not part of that test.