OFF CENTER INSTALLATIONS

We have been providing off centre installations for 40 years!

Sweden Yacht 45 - at ARC Finish - note big offset of his Hydrovane

We talked to the owner of this Sweden Yacht 45 at the London boatshow in January 2008. He reported absolutely no problem with his big offset on his Atlantic loop last year.

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UNSOLICITED EMAIL RECEIVED JUNE 2007

WAUQUIEZ 40 PS - BIG OFFSET OF 30in. / 75cm.

"Tell your colleagues."

From: available on request
Sent: June-29-07 3:03 PM
To: will@hydrovane.com
Subject: Qwyver Wauquiez 40 PS

Hi Will,

Our hydrovane, mounted way off centre, has just completed its first 500 mile passage. Everything from F7 on the nose and rough seas (North Biscay) to a gentle F4 from behind.

The Hydrovane performed brilliantly, and we are delighted with it. Tell your colleagues.

Best regards,

John Andrews & Freda Haylett

Wauquiez 40 PS - offset of 30in. / 75cm.

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For more testimonials regarding off center installations see the TRUE STORIES tab

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POTENTIALLY DISASTROUS FOR SERVO PENDULUM SYSTEMS - BUT NOT AN ISSUE FOR HYDROVANE'S AUXILIARY RUDDER SYSTEM

We often hear such a concern probably because this issue is so critical for the servo pendulum type systems. If their blade/paddle lifts out of the water the boat could instantaneously 'spin out'......imagine that in a storm! Conversely, an auxiliary rudder system, like HYDROVANE, has neither the likelihood of its rudder popping out of the water and even if it did not much would happen because:

• Even if it did lift out of the water, which would last for only a few seconds, the boat should hold course as the main rudder is locked 'on course' - preventing any 'spin out'.
• The rudder does not swing from side to side like the servo systems. Theirs might even lift out of the water when amidships.
• The rudder is longer, reaching much deeper in the water
• Anyways, the only likelihood of the rudder coming out of the water is when heading upwind - but that is the easiest point of sail for steering - most boats almost self steer themselves when 'on the wind' - needing little help from their Hydrovane.  

The only performance issue of the offset for the Hydrovane is if the rudder is deep enough in the water in order to do its work. When reaching or going downwind the boat is never heeling much and the Hydrovane rudder is deep in the water regardless of which tack it is on. Only when heading upwind and heeling substantially might the rudder, if on the weather side, be largely out of the water - and even then it probably does not matter much as that is the easiest point of sail for steering. If need be the entire unit can always be set deeper in the water to accommodate such situations. Because the Hydrovane has a longer rudder than any other system it is even less likely to have any such problem. 

About half of all the Hydrovane installations in recent years are off center.

Hans Christian Christina 43

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EXCEPTIONS

HULL FORM STABILITY ISSUES - BIG, FAST, LIGHT BOATS - Only relatively light and fast boats that are bigger (about 50 feet or 15 m.) might suffer from 'hull form stability' issues - causing the water flow, at the Hydrovane rudder to be other than the true fore and aft 180 degree direction - usually at speeds of 8 knots plus. Such pressure on the Hydrovane rudder impedes performance. The solution is an amidships installation.

MULTIHULLS - For slower cruising mutilhulls it does not really matter where the Hydrovane is located. A 50 ft. (15 m.) catamaran with its Hydrovane on the end of one pontoon reports performance even far better than he had hoped. An exception is faster boats that could have 'hull form stability' issues as explained above.

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• Yes, a big problem for servo pendulum systems but generally not an issue for auxiliary rudder systems ... and best handled by a Hydrovane.
• We used to recommend a 12 inch (30 cm.) maximum - but no longer  - having received excellent reports from far greater offsets and knowing no reason why it should be a problem.
• Practically problem free except for big and fast boats (relatively light boats at speeds of 8 knots plus)

Outbound 46

OFF CENTER INSTALLATIONS