Force needed to roll or counter roll

[fer_mayrl]

Hello,
Im just starting to look into boat physics, and I was wondering if anyone could tell me how can I know the force or torque needed to produce roll in a semi displacement boat.
I need to know this to find out how much force is needed to produce a counter rolling motion, and once I know that, y can get to getting on how to produce that force.
Best regards
Fernando Mayrl

[SailDesign]

Almost any force will produce some roll. The trick is in knowing what kind of forces are going to be generated in the conditions you are likely to expect. THEN you can start examining how to counteract them.
Puttering along on a canal will not produce much but the wakes from other slow boats, and is easily countered - being out in the open sea in a Force 8 with 10' waves is a different story. Start with what you are likely to encounter, and work from there.
A righting arm curve is not too hard to develop, given a hullform. The work needed to roll to a given angle is represented by the area under the curve to that angle. The _energy_ required to produce that roll in the time taken is a function of work and time (acceleration, assume SHM).
That should oughta get you started.
Steve