I'm basing it on my personal experience walking on Treadmaster with my own bare feet, on other peoples'
boats. Now I make no claim to having heavily calloused feet; unlike others I have known I do not walk around town barefoot. So it is fair to say YMMV. But some of us find it uncomfortable so the OP should be aware and check for that possibility himself. I should note that I am talking about the original diamond pattern; IIRC Treadmaster also has a less aggressive pattern.
I would add that I put on a non-skid made of silica blasting sand and
gelcoat, which worked extremely well when new but was also effective at scraping skin off in falls. Now the sharp points are worn off and it is not a very good non-skid but it is hell on wheels to remove. Not recommended by me...
Greg