hull sanding

[keithbradley]

I am wondering that mabe for really fast boats 100+ you need to have something even more aggressive than 150 grit....80-100 do to very fast water tension characteristics. Who knows.

I have multiple boats over 100mph. I don't sand them at all.
It wouldn't make a difference.

If sanding or polishing a boat bottom made an improvement (there are people in both camps who insist they are right), I think you would see it more on slower "sport" type boats.
For what it's worth, most people who do either notice no measurable gain.