I have a 94 Tiara 3100 Open, side exhausts, soft canvas top. Running for an hour at "no wake" speeds with after portion of canvas open and cabin hatches partially open (forward hatch closed), I have experienced max carbon monoxide reading in forward cabin of 87ppm. Can someone compare this to your cabin readings (or concerns for this level).
Tom
new to me: 1994 Tiara 3100 Open 454 Crusaders
Lifetime racing and cruising sailor throughout New England