For the most part, with a wide, flat transom and small-ish rudders, the best defense against big following seas is bigger engines. That said, not all such boats are terribly behaved, but most are at least a decent bit of work at the helm if the waves are moving faster than you are.
Bigger engines if you’ve got a good sized rudder to work w your big engine wash.
But big engines are for speed and at speed one needs a small rudder.
Fight the 5 footers or stay out of them.
Or placard it for 7 knots and/or put a bigger rudder on. But only going 7 knots you should only have half the power. Get a different boat or just fight it.
rslifkin states it nicely. As always
I don’t know of any semi displacement boat that handles waves like that well. A full displacement hull would be better. It is all trade offs. Our President 41 doesn’t like them but it certainly can handle the waves. Actually it is my wife that doesn’t like them...