How to win $1m and a Ferrari

I offer this to my new Sailing Students at the start of each course – to win, they only have to capsize the keel boat we are instructing on.

Since I am not a multi-millionaire, why am I so sure they can’t do it?

Well, it’s something called the ‘righting effect’, which is the force that pushes the boat back upright when it heels (leans) over due to the force of the wind on the sails.

This force is generated by the weight of the keel, often called a ballast keel, which coupled with the distance between the keels center of gravity and the axis around which the boat heels, creates a lever pulling the boat upright.

The righting effect.

When sailing the wind pushes on the sails, causing the boat to heel (lean) away from the wind and the weight of the keel acts as a counterweight.

As the boat heels, the Centre of Buoyancy (CB) moves away from the Centre of Gravity (CB) creating a righting lever, or arm, (GZ) which tries to pull the weight of the keel back down.

This righting force is proportional to the angle of heel (how much the boat is leaning), so as the boat heels more, the righting force increases and eventually equilibrium is reached as the wind is now also glancing off the sails, making it almost impossible to get the boat to capsize.

If we do begin to excessively heel, then the boat is overpowered, and the diligent skipper will reduce the sail area by reefing and/or trim or shape the sails to reduce power.

The other thing to consider is speed: typically, boats are designed to have minimum drag through the water at around 15 degrees of heel. So although excessive heeling may feel exciting, it normally slows the boat down, versus sailing the boat more upright.

To put things into perspective, just a little less than half of a typical keelboats unladen weight is in its keel, for example a Standard Fin Keel Beneteau 40 has a ballast weight of 5,198 lbs. and even Satori, our teaching Capri 22’ has a ballast keel weight of 650 lbs..

That’s an awful lot of weight to try to pull out of the water so I think my $1m and Ferrari are safe.