Rudder angle.

[Yarrow]

What would be a sensible maximum angle for a rudder, from straight ahead to maximum port or starboard?

 

[Aja]

Usually about 30 or maybe 40 (max) degrees either side.

Donald

 

[fluffc]

35 degrees is the normal setting for rudder stops.

 

[jwilson]

35% or 45% is a common figure quoted, but much depends on hull form. A manoeuvrable hull like a modern fin and spade form can use a higher figure, as although a blade typically stalls out at between 20 and 30 degrees angle, depending on aeofoil section, the angle of attack of the rudder on a boat once it is already turning will very different from the straight-ahead situation. Think of the stern swinging out as you turn and sweeping through the water. Once the turn has started you can use far more than 35% degree rudder to tighten the turn still more in a manouevrable hull form.

With a very traditional long shallow keel and keel-hung rudder angles much past 35% just act as brakes - though there are times brakes are useful!

 

[Yarrow]

Thanks for that, gentlemen.