This was from Chaparral site (post #17):
HMS Bounty II - Chaparral Boats Owners Club
"Ever since they rebuilt the hull a few years back, she has been floating higher in the water as a result of reduced ballast and new lighter engines. That may be the reason since in her original form she would have gone down like a rock!."
Hard to find all the facts, but I am sure CG report will address.