Boom shaped like a bow

[kirbyc1]

Could someone shed some light on the type of boom I saw that is shaped something like a bow (like a bow and arrow, not the front of a boat). It has two metal spars that have space between them, each one is bent away from each other, creating this bow shape. Any idea what there called?

[jackdale]

Nonsuch (Hinterhoeller) built a lot of these.

In the mid-1970s, Gordon Fisher, a respected Canadian sailor, commissioned designer Mark Ellis to create a design for a cruising sailboat which would have decent accommodations, but still be easy for a singlehander to manage. Ellis designed a Ljungstrom-type rig modified with a wishbone boom, on a 30 foot modern hull with a plumb bow, fin keel and balanced rudder. A beam of nearly 12 feet and cambered house-top created a large interior with accommodation equal to a standard yacht several feet longer. George Hinterhoeller, after some initial reservations about the design, agreed to build the boats, and the first 30ft Nonsuch rolled out of his shop in the summer of 1978.

[knuterikt]

A Wishbone boom?
Wishbone boom - Wikipedia, the free encyclopedia

[kirbyc1]

Ah yes that is it. The one I saw was much larger. It was on something around the size of a 28-32 ft boat. Why dont more boats use these if they are more efficient?

[jackdale]

That is a Nonsuch 30 in the photo. They built them up to 36 feet.

[JKCatalina310]

Originally Posted by kirbyc1

Why dont more boats use these if they are more efficient?

Some boats do, there are Freedom cat-ketches that use the wishbone boom on both masts. (see below)

I think the main reason they are not used more is that they don't point as well as a sloop rig. I have always liked the look and thought it would be really easy to sail.

[john1066]

They rely on unstayed masts and in their early years this was mistrusted. I think it's a good, simple rig if most of your sailing is going to be off the wind.

[jackdale]

Another big advantage to the wishbone is the versatility it gives to the interior layout. No bulkhead is needed in the middle of the boat to support the mast and the associated stresses.

[bobmcgov]

Worth noting the Wiki article was written by an advocate; like everything in sailing, wishbone booms have advantages and disadvantages. Certainly they can be fast on small craft -- windsurfers have mucho speed -- and used with a flexy aluminum or carbon stick, they can supply radical prebend useful on small, fast craft. Bet they'd be killer on DN iceboats or Lasers! They are self-vanging and, with lazy jacks rigged off the boom, act like a stack-pack when you reef or drop your sail.

Downsides: you are limited to boom-end sheeting. Where is your vanging ability when boomed far out? Your ability to control twist? Not totally lost, but your snotter isn't going to work as well as a true vang, and you can't apply it w/out outhauling the clew, taking the draft out of your sail. Most performance sailing involves decoupling sail trim features like mast bend, outhaul, and vang; the wishbone doesn't permit that. Apply one, you apply all. Reefing is harder than pulling a sail down to a horizontal boom, the boom's weight is higher off the deck, and you need either a low tack or a high clew to get the most out of the configuration. You cant ease the boom as far on a stayed mast. And so on.

They are clever and a good solution for small boats, but they are not the preferred solution on all craft. If they were, the Volvo 70s would use them, you can be sure.