Bart wrote:
....

I like your logic Jeff. My opinion also. The danger of going too
small
is not a happy one, while going too big is not a terrible penalty.

One thing I forgot to mention is that the number presumes a reasonable
prop - one that's about 55% efficient. If you use a 2 blade folder,
you might think you're underpowered. Mine work OK, but given my light
weight (10K lbs) and slippery hulls (11:1 length to beam) I really
expected to be able to power over 10 knots, but 8.5 is the practical
limit.

Also, while I think you have enough juice for your needs, I don't
think you will be overpowered. If you were using it as a motorsailer,
and expecting to exceed hull speed even when fighting a headwind,
you'd want 100 hp or more. And you'd probably be swinging a 4 blade
prop, although you can make a good case for a big variable pitch prop
on a motorsailer.