There are electric catproofing mats that might serve if you want something humane, and not just putting rat traps in your boat.
But, send them the bill for them too.
I’ve tried the repellant by Ortho and it didn’t help. What kind of mats are you referring too? I would be interested in trying it if you believe it would work. I would prefer that to taking it for a long car ride up the mountain.
BTW, I have never mistreated an animal. Just wanted to be clear on that.