We went for a demo sail once on a Witness catamaran (light cruiser-racer-type cat, that I think was 35 feet long). It had what the designer referred to as a shoe keel, instead of boards. It's like a rail along the bottom of the hull, and I think it was shaped like an upside down "T" in cross-section. The "rail" was only a few inches deep from top to bottom.

Rick and I were very dubious about whether the boat would be able to point with this "shoe." But we were amazed at how well it pointed, with what appeared to be little or no leeway.

Is anybody familiar with this concept?

Many lake canoes have one. They help alot when you are paddling solo. They also add strength to the canoe hull.

Sounds like a great way to make a skeg type bottom to protect the hulls from beaching problems. After reading the thread about planing cats thought it sounds bad for the low wetted area that you are trying to accomplish with a cat.- It would offer a lot of lateral resistance to tacking though it seems since it would be longer than a daggerboard.

John R.

Yeah, they are great for going straight. Makes life difficult when trying to turn. IF you can, go out in a canoe with the keel and in one without. There will be an obvious difference in handling between the two.

My Mystere 5.0 XL has this. It's only about 2-3 inches across. I can't be sure if it's the T skeg but my 5.0XL always pointed better than the similar non-T 5.0. I seem to point better with speed than other skeg designs I race against, especailly in a long pinching beat to weather. It does a great job protecting the skeg from beach wear since the T acts as a wide solid glass sled. I'll get a photo today.

Makes the boat turn like a truck though.

Wouter

That Witness catamaran tacked on a dime.

The Hobie Getaway has a keel shape like that. Added "foot print" on the beach to help keep the keels from digging in as much.

Fixed low aspect ratio (LAR) keels, is the 'high tech' name for these I believe.

They do not create the same amount of lift as boards do, for the same drag ratio, so racers dont use them. Going to windward in waves, they are inferior to boards.

On cruising boats they sound like a good idea, as they are useful when beaching/dry out, protect rudders and propellers in the hull, are more substantial than boards, dont snap off if you hit something, or slice the daggerboard wells.

So does the European built Hobie Twixxy

Terrible name for a great little boat though!

And also, I think, the Teddy - a very heavy small H cat.
Where do they get the names

I don't think it's the same thing. The one on the Witness only extended a few inches below the bottom of the hull and would not have done anything to protect rudders or outboard motors. It would be hard to think of the "shoe" as a keel of any kind.