Mainship trawlers have always had a reputation for serious "rock and
roll" in a beam sea.


How was this one?


*******

I can't give a fully authoritative report on beam sea stability. It was
a fairly calm day. We did a bit of waltzing to put the beam into the
largest wakes we could find- and the boat behaved fairly well. We would
take a roll to port or starboard, followed by about half again as much
to the other side, and nothing too notable after that. That's not
really the same sort of test that a steady series of steep chop on the
beam would be.

There isn't anything about the Mainship to suggest it would be a
champion of stability in beam seas. It's a semi displacement hull, with
a COG that is raised a bit by virtue of the extended flybridge/boat
deck. The hull is not that incredibly different than that on my 36, but
I don't have the weight of a flybridge, etc. What I have found with my
own boat is that a course change of even 15 degrees can make a notable
difference in stability when taking a pounding on the beam. (We
sometimes "tack" a bit to improve
comfort). Owners of a Mainship 40 might ultimately do as I have done
and make some operating adjustments to compensate for a bit of rock and
roll in certain conditions.

This is one of those cases where there is a disconnect between real
life and the
AP/Chartplotter interfaced school of theoretical navigation. Some guys
will stick
doggedly to the computerized heading, (all the while complaining about
a defect in the design of the boat), when a small change in response to
current conditions would improve the ride remarkably.

By the same token, I would not say the Mainship 40 falls into the same
class as ridiculously "tippy" boats. I was aboard a boat last week, (a
semi-d aft cabin trawler with high superstructure and a covered
"sundeck" over master stateroom), that tipped several inches in
response to placing one foot on the edge of the swimstep. Too much
vertical clearance for the draft and displacement, IMO.