View Full Version : Sail plan help

06-16-2008, 12:58 PM

I just completed and launched my new 19 foot whaleboat. I will post a video and pictures on my site Coastalrower.com The boat is also very light at about 165 lbs rigged fixed seat for one. It rows very well even with the too short oars I had on hand this past weekend. (5.6 knots in a sprint, avg 4 knots for a full hour). The boat is very tender - which I expected though that is not a problem rowing. The problems I am facing are as follows: I have designed a sailing rig of approximately 78 sq ft (leg-o-mutton). I planned on using twin leeboards for lateral resistance. With the boat being so tender I am rethinking using a plate centerboard or leaded daggerboard; though I hate to obstruct the open interior. Will weighted leeboards "stiffen" up the boat or will they counteract one another? I am open to any and all suggestions. Thanks.

Pernicious Atavist
06-16-2008, 01:13 PM
Weighted leeboards will add weight, of course, but the weight is only completely effective when the board is out of the water. The flotation the weight counters, counters the weight when the immersed. [Did I make sense there?] So, a board with say, 5# of flotation needs >5# of weight to keep it down. All that says is that when both boards are up, you have added weight on the rail. But--when both are down, she should stiffen up for you due to lateral resistance, similar to pulling a paddle towards you.

What the boards will do--especially if you use Dutch-type hard mounts that keep the weather board from flailing--is give you more lateral resistance than a centerboard because each leeboard will have to be the same area of a centerboard, and when both are down, you have twice the resistance.

Also--leeboards don't leak, don't stress the hull, get jammed up with crap, or clutter the inside of the boat. I use them on my sharpie and my canoe, and they work just fine as frog's hair.

06-16-2008, 01:28 PM
You made perfect sense, thank you. I will make a couple boards this weekend. I can always change to a removable plate daggerboard later - although it undermines the lightweight rowboat and will create turbulence. Thanks again for the input.

06-16-2008, 02:20 PM
Picture of 19 foot whaleboat.


Pernicious Atavist
06-16-2008, 02:20 PM
If nothing else, the dagger board will help the boat track when rowing. My sharpie has a skeg and it tracks great. Aside from that, I have nothing positive to say for dagger boards! Good looking hull--would be a shame to put a slot in it.

Bob Cleek
06-16-2008, 02:27 PM
Hard to really see the shape of the hull from the picture, but you may well find your tenderness problem disappears if you add some weight to the boat. Dories, for example, are notoriously tender, yet quite stable when loaded. Two or three hundred pounds of inside ballast may make a big difference. Even so, sails on small pulling boats are often really useful only for downwind work. Getting into trying to make a really useful sailboat that will work to windward out of a pulling boat is often an exercise in futility.

06-16-2008, 02:34 PM
I figured since whaleboats of the genuine type (28 feet long) worked as sailing craft that it might be nice to have the sailing option here as well. I'll be up at the Small Reach Regatta in Maine in August and I am confident with two rowers that we will be able to stay with the pack but it sure would be nice to rest a while and enjoy the breeze. Maybe I should simply start very small with the sail plan and work my way up.

06-16-2008, 07:54 PM
This sounds like a perfect application for some water ballast in several handy sized containers that can be emptied and filled as needed. Some jugs or bladder type bags to fill when sailing, and placed low. Empty them when rowing or keep a few to adjust trim, etc.


06-16-2008, 08:07 PM
CoastalRower -- You'll want a board of some sort, but one leeboard should be enough. It just needs to be pivoted on a fitting that will hold it rigid athwartships. Don't let the asymetric part bother you. It doesn't matter.

As far as stability, I'd strongly suggest sailing the boat more before you make any major adjustments. That hull shape may be initially tender, but it looks deep enough that it should settle in heeled rather than going right over. I'd spend time sailing on a lake or well-protected bay to determine whether it's the boat that's the issue or just the feel of a different type of boat that you need to get accustomed to.

When I first started sailing my Whisp, which is much lighter than your boat and probably no wider, it felt dangerously tender. But it's never gone over and I've now concluded that the issue was entirely with the skipper.

Pernicious Atavist
06-16-2008, 10:07 PM
Two leeboards. Why?
1. If fixed, as I mentioned, they'll both contribute to lateral resistance. Ensure each is big enough to do the job.
2. When sufficiently heeled, your weather board will not--NOT--work since it may well be out of the water.
3. One board you shift from one side of the boat to the other during a tack is not reasonable on anything but the smallest of boats.
4. The concept of 'only needing one board' applies to narrow boats where the board will never be out of the water. Yours seems not to be one of those.
Why do I make these claims? Because I use leeboards on different size boats and have first hand knowledge of the issue.
Water in containers or sandbags both work. I use both on different boats.

06-17-2008, 07:58 AM
As always, more good info from the forum. I will use two boards and will begin with some additional water ballast this weekend to stiffen the boat up initially. I think I may start out with a 45 Sq Ft windsurfer type sail to see how the hull performs under a press of sail. Thanks again everyone. Pictures next week with a sail hopefully.

Pernicious Atavist
06-17-2008, 01:24 PM

Jay Greer
06-17-2008, 01:35 PM
A center board can be built to work like a Chinese fan so that it can fold. This allows for a low centerboard trunk. The board can be made of sheet metal or wood. Balasting of the board with a slug of poured lead will add stability as well as help the boat carry in light airs under sail as well as when rowed against the wind.

Pernicious Atavist
06-17-2008, 05:06 PM
Jay--like the bronze [brass?] one used on old sailing canoes? Those look great and I did some research into them. Comments from the period express their discontinued use due to imparting too much drag, not always opening and closing as advertised, and getting jammed up with stuff. Seems they were used for awhile then replaced with solid centerboards and leeboards. They are cool, though!

Uncle Duke
06-17-2008, 07:38 PM
Perhaps (probably?) I'm missing something here, but is the assumption that you would have both leeboards down at the same time?
In my (mis-spent) youth I sailed on a modified sharpie where the boards were set at a slight angle to improve the 'push' to windward. Obviously this entailed some 'fire drill' when tacking (raise one, lower the other) but the owner believed it was worth it.
So - is the intent to have both down all the time? Or am I mis-understanding?

Pernicious Atavist
06-17-2008, 09:33 PM

My suggestion is to be able to have both down at the same time, thus the suggestion of having boards on 'hard' mounts, as opposed to hanging off ropes. As you probably know already, in water too shoal to have one board all the way down, both down, say, halfway, will have the same effect. Under certain conditions, both down could help stabilize the boat even more. I wouldn't sail with both down as a matter of course, but the option is nice to have.

I have hard-mounted boards on my sailing canoe. They fore and aft pivot on pins. So, when I'm running in 6", I still have control.

On my sharpie, I hang my boards from ropes, and only the lee-side board [thus the name, of course] is the working board. The weather board just kinda flutters and looks bad. So, as you note, on tack you lower the new leeboard and raise the now weather board. As you say--tacking is a firedrill, my friend!

06-18-2008, 10:10 PM
Both boards will stay down to prevent spending time swapping a single board or adjusting boards. I suppose on a long downwind run there might be some foolin with the boards, but not generally. I picked up a cheap pool cover water bag to drop on the centerline for a little ballast. We will see how it goes. Thanks again for the inputs.

Pernicious Atavist
06-19-2008, 09:16 AM
Let us see it when you're done!

06-19-2008, 01:42 PM
I find that 40-60 lbs of ballast makes a big difference in my 18' dory. I'm using two plastic covered concrete exercise weights an a 5 gallon kerosene can full of water.

Pernicious Atavist
06-19-2008, 07:00 PM
In my 16' sharpie, i use two large sandbags full of wet beach sand. Maybe, 45-60# each? Could use more!

I had to look up what a pool cover water bag is...okay, so...what are they for?

06-19-2008, 10:00 PM
They are filled with water and layed around the perimeter of the pool cover of an in-ground pool. They hold the cover in place during the winter. Really just a tube about 6 inches in diameter and 6 or 8 feet long. Full they are about 100 lbs. They only cost about 5 bucks and some even have a garden hose adapter built into the cap for easy filling. I have used them before and just lay it right on the centerline of the hull.

Pernicious Atavist
06-20-2008, 10:48 AM
I looked them up, thinking I could use one to ballast my canoe, but see they're too long, so I'll need to find something similar.

See--it never occurred to me people had to cover pools in the winter. It's obvious, but I've never seen that down here. Duhhhh.....

06-20-2008, 02:47 PM
You can buy shorter ones though the recent trend seems to be the long 8 or ten foot bags. Check directly with a pool company in your area. They make shorter ones especially for odd shaped pools.

06-20-2008, 02:59 PM
Some soft sided waterbeds use tubes about 8" dia and a little over 6' length. They have a foam pad inside them to keep the water from sloshing around and an inlet that accepts the garden hose with a small attachment. Might be something to look at.

Pernicious Atavist
06-20-2008, 04:20 PM
I need [is this a thread hijack?] about 10gls in the bow. I used those collapsible water containers like used for camp and they worked well, but split after awhile. I'll figure something out, or make my own reservoir molded to fit the boat. Two, actually, so they are impossible to remove when full, and allow me to use only one. Or I could pump them out with my bailer. Hmmmmm.... You listening, Rower? More good ideas [maybe] for ya!

06-20-2008, 08:18 PM
I couldn't find a clean one of my old "Bags" so I stopped at a pool store this afternoon and bought a 1 foot by 4 foot new water bag. Three dollars fifteen cents including the tax. BTW, you can fill them only part way and they will lay in a pile and conform to the space you put them in.

Pernicious Atavist
06-20-2008, 10:11 PM