Hull design
- Thread starter Franklin
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I would have thought that keel
shape, size and placement would have more effect than hull shape. Scows with CBs have mild weather helm as do traditional wineglass hulls, as is desirable. Sail balance (jib v. main) will also give a strong push to weather or to lee, as the forces rotate around the keel There must be some wizzes out there who can educate us. Nice question, Franklin.
shape, size and placement would have more effect than hull shape. Scows with CBs have mild weather helm as do traditional wineglass hulls, as is desirable. Sail balance (jib v. main) will also give a strong push to weather or to lee, as the forces rotate around the keel There must be some wizzes out there who can educate us. Nice question, Franklin.
Just hull this time 
Tons of stuff that go into weather helm and I don't want to start that...just wondering about the pros and cons of a tapered hull over a non-tapered hull. I know of one con of a tapered hull...it's harder to wax while in the slip
Tons of stuff that go into weather helm and I don't want to start that...just wondering about the pros and cons of a tapered hull over a non-tapered hull. I know of one con of a tapered hull...it's harder to wax while in the slip
Minimal Impact
Weather Helm comes from an imbalance of the sail plan (plus hull above waterline) against the underwater hull shape. This imbalance tends to turn the boat into the wind, and must be balanced by pulling the tiller "to weather," that is toward the wind. Taper as you describe it (flare?) of the hull above the waterline would have little or no impact on weather helm. Major causes of weather helm include: - The sailplan is too far forward. - The sail sheets are trimmed too tightly. - Blown out sails generate more sidways and less forward power. - Sails need to be reefed. Reefing both the main and the genny moves the average sail plan center of effort forward, reducing weather helm. - The design causes more weather helm if the mast is stepped farther back, or the keel is mounted farther forward. - A more rounded bow shape (in the horizontal plane) under water will add some weather helm as the boat heels. (I steer my Sunfish by sailing flat, then heeling the hull opposite of the way I want to turn.) - More heel reduces the effectiveness of the rudder (it pushes more down and less sideways as you heel.) This in turn needs more rudder for the same turning force to balance weather helm. In the extreme case, the rudder stalls, and weather helm will "round up" the boat into the wind. David Lady Lillie
Weather Helm comes from an imbalance of the sail plan (plus hull above waterline) against the underwater hull shape. This imbalance tends to turn the boat into the wind, and must be balanced by pulling the tiller "to weather," that is toward the wind. Taper as you describe it (flare?) of the hull above the waterline would have little or no impact on weather helm. Major causes of weather helm include: - The sailplan is too far forward. - The sail sheets are trimmed too tightly. - Blown out sails generate more sidways and less forward power. - Sails need to be reefed. Reefing both the main and the genny moves the average sail plan center of effort forward, reducing weather helm. - The design causes more weather helm if the mast is stepped farther back, or the keel is mounted farther forward. - A more rounded bow shape (in the horizontal plane) under water will add some weather helm as the boat heels. (I steer my Sunfish by sailing flat, then heeling the hull opposite of the way I want to turn.) - More heel reduces the effectiveness of the rudder (it pushes more down and less sideways as you heel.) This in turn needs more rudder for the same turning force to balance weather helm. In the extreme case, the rudder stalls, and weather helm will "round up" the boat into the wind. David Lady Lillie
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