first it was no #2 now it's "there all scored"?
1) Scoring alone in a diesel will not produce a zero compresion reading. Only a valve will do that.
2) Turbos are not like blowers they dont produce any boost benifits untill engine is past 60% max rpm. So you do not get better lower tork with one.
3) 80% of all our marine engine problums are realeated to cooling and cooling water problums, adding more heat in your enging compartment from your warm little round frying pan aint helping anything. Yes they do get red hot!!
4) Yes you could benifit from more horspower, but get it differently with a different bigger normally asperated engine. Whats another 1/2 gal per hour. It's a blowboat .
5) Dont be sturbon you asked for advice TAKE IT !! your getting some good advice from some knowlagable people from what I see.
6) Have the rack run on you curent engine to see if I not right on this compression issue befor you get suckkered into a new one.
I have 17 piecies of heavy equipment with a diesel engine in it. Turbos only help in some instances.
Sorry to hear about your predicament. Hind site is always 20/20
always get 3 surveys
3) Mechanical ( Hull & machanic on board at sea trial )