How about a combonation of the two?
Get a 1.5 metre by 1metre section of Neoprene, without the fabric obviously, just pure neoprene, and then maybe stick some lino or smooth plastic onto it with contact adhesive or similar.... this would create a nice slick mat, so long as you wet it first, as well as some cushioning with the neoprene.... perhaps two sheets of 10mm neoprene would be best....
As mentioned by Sheldon, you could then just roll it up and stash it.... and could also use it as a slide up the back swim platform to get those big mamas up outta the water onto the transon.... then slide back in...