Leeboard on small skiff

[hospadar]

I'm going to be installing a leeboard on a small skiff. The sides of the skiff are raked out (at about a 105 deg. angle), so if I bolt the leeboard flat to the side it won't be perpendicular to the water.

I'm wondering if it's worth it to put spacers on the hull (down by the waterline probably, I'm imagining a ripped-down strip of 2x4) to get the leeboard to be more perpendicular to the water.

It's just a little 12' fun boat It's my first build so simplicity is more important than maximum speed, but if the rake in the leeboard is really going to hurt my ability to sail, then I'd like to get that straightened out.

Another question I have is about positioning the center of effort of the sails with relation to the leeboard.

I've read that the CE should be forward of the centerboard, but I've also heard that with leeboards, the CE should be right on top of the leeboard. Again, this isn't that important, I don't care if I have a little weather helm or imperfect performance, I'm just wondering how much it matters.


Thanks again - I can't wait to sail this puppy!

[CutOnce]

I'd just clamp it on and try it on a light day. That way you could move it around till it felt right. Once you determine empirically where it belongs, you could then get fancier with the hull standoff etc.

It's small enough that you can experiment.

--
CutOnce

[BATAAN]

In Peru they take a piece of 1 X 10 maybe 5 or 6 feet long, nail a crosswise 24" 2 X 2 to one side about 12"-18" down from the top, and nail on a piece of lead sheet to the other end to weight it so it does not float. This stuff is often scavenged from pallets or old buildings.
A hole is drilled in the top of the 1X10 and another in the middle of the appropriate thwart. A piece of 3/8" rope with stopper knots connects the two holes.
To use you throw it over the lee side and the 2X2 rests on the gunnel, the leeway pushes the 1X10 vertical until the rope comes tight and also holds it in place.
To adjust for neutral helm you slide it fore and aft, adjusting the rope a little if necessary.
To tack, throw it over the other side.
No bolts or hardware, infinitely adjustable, costs almost nothing, etc.
I sometimes wonder why things get so complex.

[Plodunkgeo]

Originally Posted by BATAAN

I sometimes wonder why things get so complex.

Maybe because the very act of having a significant element of the sailing experience unattached, highly moveable and vulnerable to not being able to work, or worse, being lost overboard, makes for a really problematic scenario?

Ever lost an important tool over the side? Why?

[Doug Lord]

Originally Posted by hospadar

I'm going to be installing a leeboard on a small skiff. The sides of the skiff are raked out (at about a 105 deg. angle), so if I bolt the leeboard flat to the side it won't be perpendicular to the water.

I'm wondering if it's worth it to put spacers on the hull (down by the waterline probably, I'm imagining a ripped-down strip of 2x4) to get the leeboard to be more perpendicular to the water.

It's just a little 12' fun boat It's my first build so simplicity is more important than maximum speed, but if the rake in the leeboard is really going to hurt my ability to sail, then I'd like to get that straightened out.

Another question I have is about positioning the center of effort of the sails with relation to the leeboard.

I've read that the CE should be forward of the centerboard, but I've also heard that with leeboards, the CE should be right on top of the leeboard. Again, this isn't that important, I don't care if I have a little weather helm or imperfect performance, I'm just wondering how much it matters.


Thanks again - I can't wait to sail this puppy!

=============
Some designs that use leeboards use two with only the lee board in use at any one time. That can have some advantages including making the angle of the board virtually irrelevant. If you use just one board, the angle due to the sides may have a small negative effect when it is to windward.

[GTO]

Depending on the amount of flare at the placement point, it will be noticeable on the "bad" tack but probably not terrible.

A bigger concern will be getting the board parallel to the skiff's center line.
My board is a bit off and on the "good" tack the boat climbs to windward.

To get the angle for the board, I built the following rig:

I took a small block of 2"x4", attached a piece of AL angle to the edge leaving a 1/2" gap and ran a bolt thru the block. This I dropped into the oarlock socket.

Clamped a 2"x2" to a thwart (hanging over the gunwales) and placed eyebolts in both ends.

After U-bolting a 1/2" round tube to a piece of ply acting as the leeboard, I slipped one end of the tube into the eyebolt and the other into the oarlock "clamp".

By screwing the eyebolt in or out of the 2x2 I was able to get an angle and sliding the board fore and aft yielded a decent location.

I actually sailed with this rig for awhile, but flipping the board side to side was a hassle and I had to stop after a tack to do it.

I hope that gives you some ideas to try.

[BATAAN]

Originally Posted by Plodunkgeo

Maybe because the very act of having a significant element of the sailing experience unattached, highly moveable and vulnerable to not being able to work, or worse, being lost overboard, makes for a really problematic scenario?

Ever lost an important tool over the side? Why?

Maybe the post was not clear. A rope fastens the leeboard to the boat at all times. This is a little too simple for some. And it always works.

[troy2000]

Originally Posted by Plodunkgeo

Maybe because the very act of having a significant element of the sailing experience unattached, highly moveable and vulnerable to not being able to work, or worse, being lost overboard, makes for a really problematic scenario?

Ever lost an important tool over the side? Why?

Having one leeboard on a line that you can flip from one side of the boat to the other as you come about isn't exactly unheard of, especially on very small craft. I'm not sure why you're reacting so negatively to the notion.

And personally, I've never lost a tool over the side, as long as it had a line attached....

[troy2000]

From EF Knight:

...some years ago the author, being in Florida, on the coast of the Gulf of Mexico, took it into his head to undertake a cruise down the shallow channels that divide the mainland from the long line of palmetto-covered keys or islands that fringe that beautiful coast. He found nothing in the way of a craft available for his purpose, save what the natives were pleased to call a canoe; she was a little punt, a shallow, clumsily built trough, in shape resembling rather one of the trays in which photographers develop their plates than a boat.

He made a sail for her, and then out of a pine plank cut a leeboard about three feet long, shaped as in Fig. 42, stout at the head and down the centre, but tapering away to a narrow edge at the foot and sides. Having determined by experiment at what part of the boat's side the leeboard was most effective, he fitted an iron pin (see the Fig.) on either gunwale. A rope was then rove through the head of the leeboard, and knotted so as to prevent it from slipping through. The other end of the rope was made fast to a cleat at the bottom of the boat amidships. The leeboard could thus be easily thrown over from one side to the other, according to the tack on which the boat was sailing; the rope, being always passed over the fore side of either iron pin, kept the leeboard in its place, and prevented it from sliding aft.

Another rope, rove through a hole at the lower end of the leeboard, led aft, and served to raise it. The above is the simplest method of fitting leeboards, and the result will be found to be perfectly satisfactory. In the punt he has described, the author, provided with rod and gun, for game and fish were plentiful, undertook a long cruise among the bayous and channels of the Gulf Coast, camping out each night in pine forests on the mainland or on the sands of desert key, much astonishing the few natives he met; for a leeboard was an unknown mystery to them, and they marveled to see one of their rough country punts turn to windward so well when provided with this strange invention. The punt drew but three inches of water when her leeboard was up, and skimmed over the water at a wonderful rate.

http://freepages.genealogy.rootsweb...._leeboard.html

add: If I remember right, Ian Oughtred's Wee Rob has the same sort of setup when it's rigged for sailing. And here's a thread that also discusses the single-board-on-a-rope method: Designing a weak/failure point in a leeboard

The thumbnail is below is from Knight, not Oughtred:

[hospadar]

I think I'm going to try the roped leeboard first, it'll give me good opportunity to experiment with position/size/rake angle, since it should be easy to juggle around and change boards. If I determine it's too much of a hassle, or fails in choppy water (the great lakes) or unpredictable winds, I may change it out. I imagine in general though, if there isn't enough leeway to hold the board to the boat, that the board isn't that crucial at that moment anyways (i.e. running).

Instead of a flat board I'll probably make a symmetrical foil (since the leading edge will flip-flop when tacking), and (just because I've always wanted to do it) I think I'll pour a lead weight into the bottom.

I'll report my findings when I give it a go.

[troy2000]

Keep us posted on your progress; you can have a whole lot of fun with a boat that size.

[PAR]

You've got a simple boat, why not use a simple attachment. The board doesn't need to pivot up and down, it's either deployed or it's being moved or stowed. A simple "U" shaped plywood and 1x2 bracket that permits it to drop down over the rail, is all you need. This can be slid fore and aft to find the sweet spot, which will likely be with the CE directly over the leading edge of the board. The bracket can provide for a perpendicular orientation to the water as well. A sung fit will insure it stays put, but a whack with the heel of your hand can convince it to come off, when you want to switch sides or stow it. This arrangement has no moving parts to break or get lost and is the most common method for this type of appendage on small craft. Bolger loved this setup too.