FWIW an Albin 28 with single Yanmar of suitable HP will do for sustained 21-knot cruise. Now 24-mph might not be fast to some of you ... but that Albin hull will be able to turn screws for a 16+-mph run in seas that would have any Parker or Regulator on her knees and begging to turn around and head for the barn. Through 20+ years of publication, Powerboat Reports rated the Albin 28 TE as the #1 riding hull, followed by the Albin 25 (26?) inboard diesel CC as the #2 riding hull, regardless of sea state. In the test for the 28 TE, they said they kept it on plane in honest 8' seas off of Block Island (don't recall the speed) and that it was the best handling hull in a following sea they had ever tested.
Fast boats? Nope, but not slow either ... Some days a downeast hull will kick the pants of those Go Fasts.
Just don't buy a 28 TE with GM Penninsular diesels :shock: !