Normally, my catamaran powers at about 7.5 knots, but on its last trip
last fall, it could only muster about 6 knots. I assumed it was do to a
foul bottom as the boat had not moved for the previous month, and I had
gone 2 years on the bottom paint. Indeed the bottom, and especially the
aft sections around the saildrives, was a mess, both with barnacles and
some type of small clam-like critter.

I didn't think much about it until someone at the yard said he had the
same problem - his Seidleman could only get to 4 knots at the end of the
season, and he said other owners reported the same thing.

So my question is, was last fall particularly bad for growth in New
England, especially Boston Harbor?