Spec sheet says 500 for sceptre 23’, If I have the right model on here:
http://www.classicseacraft.com/Sceptre23.htm
In absence of a manufacturer spec this is to be used:
(Length x transom width x 2)-90= uscg hp rounded up to nearest multiple of 5
Even if I gave it the full 8’ beam which I’m sure it’s not. You have
(23’x8’x2)=368-90=278 rounded to 280
https://newboatbuilders.com/pages/hp.html
As others have stated the deep v takes lots of hp. This calculation doesn’t seem to work on Seacrafts. I back into it through our spec sheets, catalogues, and engine price lists.