Since the publication of The $50, 5 Hour Canoe Sail Rig approximately
one year ago, I have continued to experiment with the design of
the sailing rig. I have found that with minor modifications to
the leeboards, boat handling is easier, and performance is improved.
I would like to pass along some of the lessons I've gleaned.
Leeboards
1) I have moved the leeboards 9" aft. (Originally the
leading edge of the leeboard was 51" aft of the eyebolt that
joins the heel of the yard to the deck. It is now 60".) This
results in better helm balance: the canoe will still luff up and
turn into the wind, but less force is required on the paddle to
maintain a steady course. (The exception is in very light breezes
when the canoe has a slight tendency to turn downwind--not a dangerous
tendency in light breezes.)
2) I have dramatically reduced the size of the leeboards. Originally
I called for the leeboards, operating simultaneously, to be 4%
of the sail area. When one leeboard was accidentally disabled,
I noticed that handling and speed both improved. I have consequently
removed the closet-rod thwart at the top of the leeboards and
replaced it with a short length of cord. The leeboards have thus
become self-activating. Upon changing tacks, the leeward board
digs in, putting tension on the cord and drawing the windward
board completely out of the water. Now, as a result, the submerged
surface area of the leeboard is approximately 13.5" x 6"
when the canoe is at rest. When the canoe is heeled over
fifteen degrees, the submerged surface area increases to 15"
x 6" or ninety square inches. This represents about 1.5%
of the surface area of my 42-square-foot sail. This also likely
represents the bottom limit of leeboard area. I have tried even
smaller ones and leeway increased noticeably.
3) Instead of 3/4" plywood for leeboards, I now use 1/2"
stock. It is sufficiently strong and it cuts the leeboard weight
(and possibly water resistance, too) by 33%.
Sail
In hopes of becoming more competitive with the most popular daysailors,
I have been experimenting with a larger sail. I wanted to maintain
the 11' 8" length of the yard (in order for it to stow under
the seats). Since I wanted a taller (as well as larger) rig, I
lengthened the upper sprit (or batten) and raked it at a more-nearly-vertical
angle. There are a number of bugs that need to be worked out of
the new rig. Though the new rig is faster on a reach or run, upwind
performance does not seem improved. It appears that part of the
problem is sail twist; the upper part of the sail is luffing while
the lower part is properly sheeted in. A second difficulty-- confirming
doubts expressed in the book--is that closet rod is not strong
enough to handle the additional sail area.
Hardware and Fittings
While tinkering with the larger sail, I have simultaneously been
tinkering with the hardware and fastenings. I thought, for example,
that it would be nice to mount the heel of the yard in a slide.
With this improvement, the angle of the yard and the height of
the rig could be instantly adjusted. Reefing could be accomplished
by simply pulling a pin, pushing the yard forward and reinserting
the pin. Because the center of effort shifts when the angle of
the yard changes, helm balance and steering are also be affected.
There is--in other words--a good deal of potential in this minor
modification, but it may take years of grueling, selfless research
to exploit it fully.
With the yard placed on a slide, the junction of the mast and
yard can become permanent. There is no longer any need to slide
the mast up and down the yard, retying it in a new location. This
prompted a series of very ill-advised experiments with a variety
of metal fastenings: EMT brackets, bolts, baling wire, hose clamps
and so forth. None worked worth a flip. Because of the bending
and flexing inherent in this joint, the weakest "link"
in a metal "chain" breaks in about an hour. I have reverted
to 3/16" nylon line. Relatively speaking, it lasts forever.
I tried substituting one inch (1/16" think wall) aluminum
tubing for the closet-rod yard. It flexed unacceptably in only
a 12 knot breeze. The next step up is 1/8" thick walls. But
at one-half pound (or more) per foot, this is probably more
weight aloft than desirable. I have since fabricated spars of
wood, plywood and epoxy. Too late in the season, unfortunately,
to run any rigorous tests on them.
In the coming year, I hope to test some other options.
- A modified standing lug. the head of a lug sail should be
less inclined to twist than my enlarged, adulterated lateen.
The potential, then, is for a larger, more weatherly rig on
shorter spars.
- Leeboards mounted on a vertical pivot. This would allow me
to make course corrections by varying the location of the leeboard.
(Essentially the inverse of the windsurfer steering process)
If it works as hoped, a steering paddle will no longer be required.
- Lexan skegs: one forward, one aft. A leeboard's worst liability
is the water it traps against the hull. Waves get squeezed in
the narrow passage and water gets kicked into the air. From
here, the water--with unswerving inevitability--goes into the
bottom of the canoe. Since a canoe's course can readily be changed
by shifting weight (forward = turning upwind; aft = down) leeboards
are required only to prevent leeway; not to assist in steering.
With a little luck (and more grueling, selfless research), we
might be able to replace the leeboards with two small, strategically
placed skegs. Payoffs might then be experienced in a number
of areas: dryness, weight, performance, reduced water resistance,
convenience of operation and possibly even stability.
If my good intentions hold, I will make the results of this research
available on our website next year at this time. I will also pass
along the experiences of any others who care to share them.
Any and all builder/user/experimenter feedback will be included,
provided, of course, it is unctuously complementary.
Share your thoughts and experiments.
