Re: [BCC Forum Post] Adventure: Mast rake

In setting up mast position in a racing dinghy the usual procedure is
to keep track of the distance from the masthead halliard sheave to the
transom or some other fixed point, and the foot of the mast to the
transom or som other fixed point. On then can compare these to known
successful settings used on other boats of the same class, or one’s
own boat during different conditions of wind and wave chop. The same
ought to work for a BCC but I have never tried it on Itchen, mostly
because the adjustment possibilities are so limited compared to a
typical dinghy, such as the Albacore I raced for many years. Last time
I tinkered with Itchen I just moved the mast step adjustment as far
aft as was convenient and took up as much as possible on the headstay
turnbuckle before tensioning the backstay.

I have a suspicion that much of the “weather helm” experienced on some
BCC’s derives from old blown-out mainsails with the center of effort
too far aft, or failure to reef soon enough. A cunningham will help by
moving the draft forward a bit, but I seldom bother wiith Itchen.
Itchen is certainly way overdue for a new main, not because I any
longer have much interest in getting to a windward mark a few seconds
ahead of another boat, but to reduce weather helm and provide more
punch going to weather in a steep chop. Anyone else have experience
with this on their BCC?
s/v/ Itchen BCC #73

On Tue, Mar 9, 2010 at 2:33 AM, BCC Forums wrote:

Author: Adventure
Username: Adventure
Subject: Mast rake
Forum: BCC Forum

Since re-installing the mast after a major renovation last year, I have been experiencing varying degrees of weather helm.

I know that Roger’s advice is that we should be set up with zero aft rake, and his advice on how to check this definitively depends on levelling the boat in the water, using the waterline groove in the hull, before setting up a plum bob.

My problem is that I can’t locate the groove. The boat is in the water for the time being, and I won’t take her out till the summer, when it often gets up to 118 degrees ambient, and it’s a bit uncomfortable…!

No doubt if I were to sand down the paint while she’s out of the water, I’d find the groove, but how to ascertain that the boat’s level now?
Any ideas ?