I'd think a vacuum sander would be the minimum. Without one you may be spreading a lot of fine dust and not realizing it.
I had a 1950's fishing boat next to me last winter and the owner was taking the hull down to re-finish. I got down one saturday afternoon and my deck and cockpit were turned blue with sanding dust.
I got his attention and he was mortified. Said he'd pay the yard's detail guy to clean my boat. I suggested we split a six pack and clean it off with some boat soap and brushes.
No harm done. But if that blue paint dust had baked onto the gel coat over a couple of weekends it might have been a different story. BTW, there was little or no wind, just fine airborne dust. He used a vacuum with his sander after that. No more problems.
Always a good idea to be a good neighbor...
95 Catalina 30 Island Time
“If a man is to be obsessed by something, I suppose a boat is as good as anything, perhaps a bit better than most" - E.B. White