Sailing on the Cheap: a Real JonBoat Rig
(and a poor man's fast motorsailer to boot!)

Tom Sawyer and Huck Finn would have been right proud of this one. I've wanted to put a sail rig on a jonboat (on the upper Mississippi we call them flatboats) for years.
A great day for sailing! Note offcenter rudder, crooked mast, and white leeboard clipped to port side. It works!
Bill Mantis' installment article "Sailing On The Cheap: An Experimental Rig For A Jonboat" in the June 15 to July 15, 2000 issues of Messing About in Boats, spurred me into action. A followup reader commentary in the August 1 issue emphatically stated "it simply won't work" and urged "any motor-boater looking to convert such a vessel to abandon the idea immediately." That really got me going! Though I appreciate Mantis' articles, I prefer an empirical approach over armchair theorizing. His bipod rig was intriguing, but the custom welded rigging didn't look "on the cheap" to me. Besides, I hypothesized that the canted leeboards which were the inspiration for the bipod rig in the first place were not necessary.

The idea here was to spend little or no money on the rig, in order to mesh with the concept of using a readily available jonboat on the cheap. And build it quick! So we're talking about an afternoon or two, duct tape, polytarp sails, a few sheet metal screws, clothesline, and a bowsaw to hack down a few locally available saplings. Spars were green willow, chosen because it was the only species that could be legally cut on the nearby wildlife refuge, and it grows somewhat straight in the needed lengths. The rig is an "Arabian lateen" or "settee", #21 out of Bolger's "100 Small Boat Rigs", selected because Bolger said it would work well with a bendy yard, which would flatten the sail. It's wonderfully low-aspect, the yard can be kept light, its very simple to rig, and no boom to slap you in the noggin.

Here's how we put her together:

Gray (to match the duct tape) polytarp (8 x 10) is folded over the yard in the desired "Arabian lateen" shape. The yard is a little crooked, so I first oriented a crook upwards to serve as the halyard attachment point.

Then I folded the sail as best I could over the crooked parts, and trimmed the excess. The yard sleeve is then duct taped right over the yard. No stitching or double-sided tape - we're talking a very quickly built experimental sail, to last for a half dozen or so outings.

Completed sail. Darts are duct taped in at the tack and throat to shape the sail, fastened on both sides. Very little rigging needed!
Masthead "sheave", formed with a couple gouges from the grinder, rounded out with a round file. Becket is a thick strap of willow bark. If I had more time I'd do a proper lashing to secure the becket, but hey, this is a quick project, and I'm not averse to a loop of duct tape! Friction on the halyard was not an issue at all on this scale.

An initial experiment using an oar to steer convinced me that a real rudder would be nice. This is a Michalak-style kickup rudder, shown in the "up" position. Counterweight is steel shot cast in place with epoxy. Payson-style eyescrews (epoxy in!) and dowels for pintles and gudgeons.

Rudder in the "down" position. Tiller is a willow sapling, with a slot gnawed out with a skillsaw for the rudder head. Tricing line used to hold the rudder up for beaching. This rudder worked amazingly well, and was very quick to build. There's also a wingnut on the rudder pivot to control the amount of friction and play.
A bone in her teeth even! "Weedless" leeboard. The angle of this leading edge was more than sufficient to shed the "eelgrass" (wild celery - Valisneria) that is very common on Lake Onalaska. Bolger-style "clothespins" hold it on, hacked out of some oak-slab firewood. It easily kicks up when hitting obstructions. It flares the wrong way on one tack, but it must have worked fine as we did not have too noticable of leeway.
Sail plan for 14' x 36" (bottom) flatboat. 73 sq feet. Could be larger for light air.

So, how well did the jonboat work? Well, did you ever *row* a jonboat?? That will give you some idea, but it really was not that bad. The boat seemed to slide thru the water much more easily than I expected. It didn't *feel* sluggish, though you could always hear the water being sucked along into the big hole at the transom. Of course a little rocker, deadrise or taper would help that, but then it wouldn't be a jonboat. I guess a little sluggishness is not nearly so bad if you're not sweating it out at the oars. Maybe it won't win the America's Cup (at least not without the engine), but this rig is plenty fast enough to have a whole lot of fun!!

Backwater Boats (aka Fritz's Boat Page)

Author/Contact:  Fritz Funk (