I have been gathering information on rudders – see my posts here and here.

The following by J.D.Sleightholme in his ABC for Yachtsmen, is useful.

Published in 1965, original price 21 shillings, and bought in one of my favourite secondhand bookshops –  Books by the Sea, Bude, Cornwall.

The question is what effect Blue Mistress’ rather heavily-built rudder have on her performance?

It’s one of those subjects that has several different answers depending on who you talk to. At the moment I’m gathering information and listening.

Blue Mistress’ heavily-built rudder.

Mr Sleightholme writes:

“A yacht should handle with the minimum use of the rudder (which slows her).

Deep narrow rudders are more effective than wide ones and have less slowing effect. As a rule, deep rudders are broader at the top due to difference in water density.

A steeply raked rudder exerts additional force in pulling the stern down when hard over.

In tacking with good way on, very little rudder is used at first, but more is applied as the speed drops – (never more than 30 degrees). Jamming it hard over may mean missing stays.

Power craft have proportionately smaller rudders because they work in the slipstream of the propeller. May be “balanced” with a small area forward of the rudder post.

Sailing craft may have 12 – 15 per cent of immersed lateral hull area in the rudder, power craft about 5 per cent.” (p.100)

This says more about shape and angles and less about weight, but it takes us in the right direction.