Daggerboard in Dedicated Sailing Canoe?

[garypete]

Hi Sailers,
As a newbie to canoe sailing, I'm hoping someone can give me some good advice before I take a Skilsaw to my wooden canoe.

I'm converting one of my cedarstrip canoes, an 18' EM White Guide model, into a dedicated sailing canoe. I'd like to cut into the hull for a daggerboard well so I can sail singlehanded without having to deal with leeboards.

To prevent catastrophic hull damage in case of running the lowered daggerboard aground in shallow water, I plan to build the 4'-long weighted daggerboard with a pivoting mechanism located about 12" under the hull. If the daggerboard was fully down and I stupidly sailed the canoe onto a submerged rock bar (a likely scenario for me), the bottom 2' of the daggerboard would swing back on the pivoting mechanism.

If the submerged obstruction is less than 12" deep, the pivoting mechanism won't help and I'll probably tear the daggerboard well out of the hull. C'est la vie.

As envisioned, the pivoting mechanism will be a single 3/4" stainless steel bolt tightened to a torque value that it would give way and pivot only by an extreme shock--like hitting a rock at sailing speed. During normal sailing, the daggerboard would remain fully extended 3' beneath the hull.

I know that the logical way to prevent rock damage would be to simply build a swing-down centerboard or use a folding fan centerboard. For various reasons, those are not options here; it must be a removable daggerboard, lead-weighted on the lower 12" for ballast.

Has anyone built such a contraption that they could advise me on the possible problems I might encounter? I'm needing help here, as I know just enough about canoe sailing to be a danger to myself.

 

[Fitz]

leeboards

I know I'm not answering your question, but someone will ask, so it might just as well be me. Why not use leeboards? You can easily sail singlehandedly with them and they don't require major surgery on your canoe. If they hit an obstruction, they will pivot up.

There was an old OT posted on here a month or so ago by Kevin Martin that had a center board. Here is that link:

http://forums.wcha.org/showthread.php?t=3994

 

[garypete]

Portaging leeboards?

Fitz,
That's a fair question.

The Guide is a great tripping canoe, and I may still use it for trips into the Quetico or points north. With the huge lakes there, sailing is an attractive alternative when these old arms get tired. So a "wilderness sailing rig" for the Quetico must be light, compact, and portageable. Folding leeboards are none of the above.

I'm going to commission Todd Bradshawin Madison to make me a loose-footed spritsail requiring only a single mast and lightweight sprit. That mast will either be a telescoping aluminum affair, or will be a length of Canadian spruce found enroute. Ditto for the sprit. The steering will be by paddle, and a spare paddle--built specially for the purpose--will fit down into the daggerboard well.

 

[Benson Gray]

a "wilderness sailing rig" for the Quetico must be light, compact, and portageable.

Leeboards are not required at all if your intent is to only use this downwind as you probably know. Another option if you want to go upwind is to reinforce the side of the canoe at the middle thwart area so that you can bolt the angle bracket for the leeboard directly on to the gunwale. Then you could build a mechanism that would clamp around the shaft of a heavy paddle to use as a single leeboard which could also be bolted on the pivot hole in the leeboard bracket. This might require making the grip and shaft end of the paddle removable as well so that it doesn't get in the way of the sail. It is likely that all this would weigh less than your pivoting daggerboard with lead weight and waterproof trunk. Let us know what you decide to do and how it works.

Benson

 

[garypete]

Leeboard Pivoting on Reinforced Gunwale Bracket

Now there's a novel way to reduce the parts necessary for a leeboard system!

If the custom wide paddle (used sometimes as a wilderness leeboard) had a quick-connector for the shaft like those used with breakdown kayak paddles, the shaft could easily be removed, solving the boom-interference problem.

I think I'd simply drill a hole in the paddle for the pivot bolt on the gunwale bracket.

Might a single leeboard (clamped paddle) suffice to stop slippage and allow sailing on most points of sail?

 

[Todd Bradshaw]

While a paddle in a clamp might certainly be possible, it's only as good as the paddle and the clamp. Most leeboards have more surface area than a paddle blade, so you might need to design some sort of big paddle with being a leeboard as one of its it's major design criteria.

As far as daggerboards go, installing a daggerboard case makes a major stress riser (stiff spot surrounded by more flexible stuff) in the middle of the canoe's bottom. This can be a serious weakness if you hit anything. I like the way Old Town did it on the old fiberglass Wahoo model, where they built twin daggerboard wells, but stuck them off to the sides in a spot where the hull is already much stiffer and the gunwale structure was close.

I really think weighting the board down with lead isn't at all needed or desirable. It's one thing to have fifty or sixty pounds of plate steel centerboard on a dedicated sailing canoe that you trailer to the lake for daysailing, but a few pounds of lead on a daggerboard sounds like more trouble than it's worth.

If I wanted to build a kick-up daggerboard, I would do it like this - with a circular board riding against rollers inside the trunk and a light hunk of shock cord to keep it down. If you hit something, the board just raises. All in all though, I think leeboards are probably just as practical and as mentioned, you don't need to saw a hole in the canoe to use them.

 

[garypete]

Elegant Solution!

The angled, semi-circular daggerboard riding on rollers is simplicity itself and a great solution I think I'll use.

Duh. I should have read Canoe Rig again as I'm sure it's in there.

If you feel that just a lightweight wooden daggerboard will suffice, that's an item I can easily portage when doing wilderness tripping. So I don't need to make a special spare paddle to use as a wilderness daggerboard.

 

[Pernicious Atavist]

Do keep us abreast of your efforts. I'd like you to share your project with us at Canoe Sailing Magazine, so take a lot of photos! I think most, if not all of the readers here also read CSM, so we'll all enjoy your work in that venue.

Todd--what an interesting board! Is that an extant model or something you thunk of for this case?

 

[Todd Bradshaw]

I'm not positive, but I think I originally saw the circular board in Chris White's book "The Cruising Multihull". Daggerboards are great in multis because they use a small hole in the hull, only slightly bigger than the cross-section of the board itself - but at those speeds, the potential for grounding damage is obvious.

I'm still not too keen on the idea of building a big stress riser into the bottom of a perfectly good canoe hull, or the five to ten pounds of structure that it will probably require to build the daggerboard well. It brings up a whole bunch of "if you're gonna's":

- If you're gonna' build in a daggerboard and start limiting its use as an all-around canoe, you might as well also build in some decking.
- If you're gonna' build in some decking, you might as well make a couple of really big watertight compartments so that the boat is self-rescue-able.
- If you're gonna' go that far, you might as well go asymmetrical and broaden the stern sections a bit, so that the boat has something back there to plane on.
- If you're gonna do that, you might as well put some sort of high-powered, higher-aspect rig on it to really get some speed out of it.
- etc. etc. etc.

You can, of course, stop at any point in this scenario and say "That's enough", but it does maybe show the value of a simple pair of leeboards that you leave hanging on the garage wall on days when you just want to go paddling.

 

[Pernicious Atavist]

Yes--I think all us experienced canoe sailors agree--leeboards are best. They don't stress a lightly built hull, which a canoe typically is; they don't leak, which centerboard trunks invariably do; and they don't get jammed up with crap when running into shoals or beaching, which centerboards often do. But that's just us, isn't it?

 

[garypete]

Something Back There to Plane on...

If you're gonna' go that far, you might as well go asymmetrical and broaden the stern sections a bit, so that the boat has something back there to plane on.


Strange you should mention that, as I'll admit I've been mulling over some way to plane a canoe ever since I read a fascinating book about the then-emerging hydrofoil technology decades ago entitled The 40-Knot Sailboat.

Written by a backyard tinkerer, with a PhD in Messing Around in Small Boats, he installed hydrofoils on the hull and outriggers of a long narrow sailboat, overpowered it with a high-aspect mast and monstrous sail and was actually clocked at 40+ knots. I do remember that turning the planing contraption was problematical and he ended involuntarily beaching it at about 35 mph totaling the boat and nearly himself also.

Has there been any real interest in sailing hydofoils?

 

[Pernicious Atavist]

Lots of hydrofoil interest...but not lots in hydrofoil canoes...yet

 

[garypete]

Canoe Hydrofoils?

It's the short days of the winter solstice, it's 20 below out, and there's a foot of new snow to blow out of my long driveway. Nothing like mulling over next summer's boat design to get away from all that for awhile. But hydrofoils on a canoe is a little extreme even for me; I don't think I'll go there.

I was thinking more along the lines of a couple fold down "planing panels" hinged along a spray rail installed at the 4" waterline in the rear quarter of a canoe. With a surface area just big enough to prevent the stern from squatting as displacement hull speed was exceeded and provide lift toward planing as speed increased.

 

[Pernicious Atavist]

Gary, when I find myself going off the deep end[happens a LOT] about modifying a canoe, I realize it's time to considering building something else to sail in addition to my canoe.... This may be one of those times.... Yeah, I've contemplated hydrofoils for mine, but realized I needed to look at another type boat. Now--here's an idea--would you like to sail above 17 knots? How about building yourself an IC or Swedish type? I have a couple articles in CSM that may help.

 

[Dan Miller]

- If you're gonna' build in a daggerboard and start limiting its use as an all-around canoe, you might as well also build in some decking.
- If you're gonna' build in some decking, you might as well make a couple of really big watertight compartments so that the boat is self-rescue-able.
- If you're gonna' go that far, you might as well go asymmetrical and broaden the stern sections a bit, so that the boat has something back there to plane on.
- If you're gonna do that, you might as well put some sort of high-powered, higher-aspect rig on it to really get some speed out of it.
- etc. etc. etc.

http://abm.org/canoe-sailing.asp

 

[Dan Miller]

Yes--I think all us experienced canoe sailors agree--leeboards are best.

Speak for yourself, Ed, my daggerboard canoe works great!

 

[Fitz]

Contraptions

By the way, I see that a fella by the name of "Andre' made the Launchings section of WoodenBoat this month sailing one of them thar contraptions.

 

[Andre Cloutier]

Fitz the Spoiler

Kool, we've moved and I think my mail has gone where the lost socks go. Thought it might have been in this issue, now I have to go buy a copy or two, thanks for the heads up. Loved the shot of your house all covered in snow, it looks great. Have a Merry Xmas, I'll post some shots of my latest acquisition when its back home in the garage (and my key fits in the front door again; its cold in the doghouse) .

 

[Pernicious Atavist]

Dan--can you portage that thing, cute as it is?

 

[Benson Gray]

can you portage that thing

Sure, that's what carts and trailers are for as shown at http://forums.wcha.org/attachment.php?attachmentid=2393&d=1166039533 and elsewhere. I can't easily portage my eighteen foot Otca sailing canoe with sponsons by myself either.

Benson