Windvane on a catamaran

[Talbot]

Where should a windvane be fitted on a Cat? my assumption is that it should be on the centreline. I have wheel steering. Should I get a windvane attachment for my existing autohelm 3000, or what type of manual steering vane would be suitable for a 30ft cat?

<hr width=100% size=1>

 

[Mirelle]

Caution! Multhull breakaway effect

This depends very much on the type of multihull. A heavy slow cruising type, or a Wharram type, may be immune, but the "received wisdom" is that wind vane steering should not be fitted to higher performance multihulls.

The reason is that the vane gear operates by sensing the apparent wind, and maintaining a constant heading in relation to that. With a displacement single hull, no problem.

With a cat or a tri, acceleration can be dramatic as you no doubt know - its part of the fun! However, the downside is that if it is set up for close hauled, in a gust or a squall, the vane gear will keep trying to keep the apparent wind where it was, as the boat accelerates. This has the effect of the gear bringing the boat round onto a broad reach, with the sheets still pinned in, as the gust increases in strength.....a recipe for a capsize. This is why racing multis all use compass sensing autopilots, not vane gears.

Don't know if this would be a problem in your case, but thought I should mention it.

<hr width=100% size=1>

 

[timevans2000]

Re: Caution! Multhull breakaway effect

I was considering one for my Prout 37. I wouldnt consider her a performance multihull like the new breed of modern cats but she has a large rig with performance sails. She can accelerate rapidly especially in a sea that allows her to surf. Any idea if a vane steering system would work ?

<hr width=100% size=1>

 

[Mirelle]

Re: Caution! Multhull breakaway effect

I'd be cautious. She may not be going in for the Route du Rhum but she's a big, fast. boat! I would suggest talking to the designers and to the windvane suppliers before making a commitment.

<hr width=100% size=1>

 

[Talbot]

Re: Caution! Multhull breakaway effect

My boat is a 9m Catalac. No-one in their right mind would call her a performance boat, but even she will accelerate quite quickly. I guess it is a trawl through the makers to try to get their take on it.

<hr width=100% size=1>

 

[Boathook]

They never recommended the autohelm windvane because of the acceleration even in the Catalac ! Compasss ones are best though the motion can make they work constantly. Now if I could lay my hands on a oil filled compass to talk to the autohelm 3000 ......

<hr width=100% size=1>

 

[Birdseye]

Re: Caution! Multhull breakaway effect

There was an article in one of the Prout world magazines written by a guy who successfully fitted a specially made vane to an Escale and sailed it to south america. The boat was given a weird and unpronouncable Irish gaelic name and I think the man himself had worked for Prout. More than that, I cannot remember.

Phone Rob Underwood at Broadblue - he will no doubt be able to give you details.

Personally, I have gone for solar panels and an autohelm on my Prout.

<hr width=100% size=1>