Sailing With A Boat With Twin Rudders

[Kayamore]

We recently went sailing with someone with a sailboat with twin rudders. The boat was more than 25 years newer than ours. We went out expecting the boat to be faster than our 1976 32 Ft. endeavour. It sure wasn't. Does those twin rudders make a big difference in spead?

[ohdrinkboy]

A lot depends on how clean each bottom is, the condition of the sails, and the quality of the sailors. Look up the PHRF rating for each boat. The lower number is the faster boat in general.

[Ex-Calif]

I doubt the twin rudders are for speed.

More likely they are to put a rudder straight in the water when heeled for better control.

[Hydra]

On some yachts, the twin rudders aren't for speed but for standing upright when taking the ground. Example: Beneteau Oceanis 311 DL.Bénéteau OCEANIS 311 DL - Occasions - Voilier de grande croisière

Alain

[David M]

They are also so that boats with fairly flat hull cross sections (not much deadrise) still have all of a rudder in the water when they heel.

[Andrew Troup]

The best setup of all (I reckon) is twin (transom hung) dagger rudders, so you can retract the windward one. Less wetted surface in light conditions, less stress on the blade from smacking the water surface when it's rough (and sometimes kicking the back end of the boat around in the process)

If you break one blade, you can get home in good shape by swapping it from side to side when you're doing long tacks.

Certainly they're not for speed, unless you equate control with speed (which is true in the sense that you can carry more sail on a reach when it's blowing if you have more a effective rudder)

[Snowpetrel]

The only boat I sailed with twin rudders was an old open 60. It never seemed to steer very well down wind, I suspect because the windward rudder alternately bit in then cavitated as the boat rolled.

She would start to round up, the windward rudder would cavitate and stall and she would need a lot of helm to bring her back down, then as she leveled up she suddenly would spin around into a gybe if you weren't real quick pulling off the helm you just applied seconds before to control her.

The rudders were also a real pain sticking out the side like that, catching seaweed and every chunk of ice that went past. They were also extremely vulnerable if the boat ever grounded. And they caused a lot of friction in the steering.