Stoa Proa Update
click here to read or make comments about this  article
designs by Gary Lepak - Port Angeles, Washington - USA

Well, I have finally gotten around to making some improvements on the Stoaproa and getting some pictures taken on the water.

Safety Sponson

click to enlarge

I have added a "safety sponson" to prevent capsize from leaning too far away from the ama. The ama weighs only 7 lbs and with an overall beam of only 4' there have been a couple accidental capsizes by friends while paddling. The possibility of capsizing has always made me nervous too, and made me afraid to sail it in all but the very lightest wind. The new sponson solves the problem and still allows enough space to paddle between it and the hull. The sponson can slide right up against the hull if I need to enter or exit from a dock. The background is Port Angeles Harbor from Ediz Hook, the sand spit that forms the bay, with some of the Olympic Mountains in the background.

click to enlarge

I spent some time at a local lake, Lake Sutherland, this summer where it was warm enough to not mind getting wet, unlike the local 50° saltwater. This picture shows the stability offered by the sponson, which is 4" square and 8' long. The top is 1/4" ply and the pink foam is covered with one layer of 6 oz glass and epoxy.

Capsize Recovery

click to enlarge

I capsized the boat by submerging the ama and pulling the hull over. The ama displaces about 60 lbs, small enough to submerge but enough buoyancy to lift the main hull mostly out of the water as it rolls upright. This picture shows the beginning of the righting sequence. The Mirage drive hole makes a handy place to grip the hull.

click to enlarge

As the hull rolls upright, most of the water bails itself out at about 90°. I didn't get a picture of the moment the boat flipped back upright, but in this picture I have swum around to the other side and submerged the ama again to get more water out. With a bit more foam in the ama, it would bail itself completely.

click to enlarge

Climbing back in is easy between the ama and the main hull. There is no risk of re-capsizing.

click to enlarge

This is all the water that was still in the boat after righting. With my weight at one end, this shows the deeper end of the pool. Spread out evenly, it would be about an inch or so. The water level in the Mirage drive well shows the usual draft, about 4".


click to enlarge

A couple years ago I tried sailing with a small tarp lugsail. As I mentioned, I never developed the sailing rig because of fear of capsizing in cold water. This summer after making the safety sponson, I sewed up a little sprit sail from tarp and had a good time sailing on the bay and the lake. I have been sailing it as a tacking outrigger rather than a shunting proa, as it is not worth switching the sail to the other end and with the banana shaped paddling ama and sponson I try to keep both of them out of the water as much as possible on both tacks. I especially enjoy sailing it with the ama to windward, just kissing the surface or flying just above it, but it is a balancing act to keep it there with the main hull being only about 16" wide at the waterline and the windforce fluctuating quickly. The sail looks better when there is some wind in it.

click to enlarge

Last weekend I took the boat to Port Townsend, 45 miles from here, and was lucky to find a used sail in the local marine salvage store for $60. It was an almost perfect fit for my 14' windsurfer mast and sprit boom, so with the tools and a few screws I had with me I got it to work and had a great time for few hours sailing along the waterfront of this Victorian maritime town, the home of the Port Townsend Wooden Boat show. It is a Neil Pryde sail about 45 sf from a Quartermaster 8 dinghy made locally by Vashon Boat Works.

click to enlargeThe size is perfect for the Stoaproa, but it will need some reef points for winds above about 15 knots. I got into some afternoon westerly gusty wind blowing me away from shore and with the limited buoyancy of the ama and sponson, my limited ability to steer with the paddle and lean to windward at the same time, I had to sheet out quite a lot in the gusts. I had the Mirage drive in place and had been using it off and on all day, so simply pedalled straight back to windward with the sail flapping in about 15 knots of wind to get closer to shore. It also needs a larger leeboard for this new sail. I was impressed that the Mirage could make good progress against the wind with the sail flapping. If I had to I could have pulled out the mast, rolled the sail around it, and tied it to the crossbeams to reduce windage. It is a sleeve sail not designed to have a halyard, but I will add that capability.

What Next?

Although it is a lot of fun to sail as it is, there are improvements to be made, mainly to make it more relaxing and handier. I've considered making it a shunting proa with a larger ama, but the rig and steering complications would take some time to work out, and steering with a paddle can be inefficient and gets tiring. Also, when pedal/sailing the Mirage drive would have to be turned around in a shunt too. I also thought of building a quick and dirty ply hull of similar dimensions and sailing it as a catamaran, which I probably will do some day to make it more of a camp cruiser that could be beached or slept onboard. I may do both of those eventually, but for starters I have decided to make two new amas for it and sail it as a trimaran. They will be 12' or so with a lot more buoyancy and less rocker than the present paddling ama. With the amas just above the water I will still be able to sail just on the main hull when I want to put in the effort to balance it, or I can sit back and relax and let the ama do its work. I'm planning on making the height of the amas above the water adjustable. I'll make a larger leeboard and probably have a strap above the waterline to hold it in place on both tacks. I'll add a rudder with a yoke and long extensions or lines so I can steer with my back to it with either my hands or feet. I'd also like to set it up to row with a sliding seat, as that is a form of exercise I enjoy and I think will move it along faster than the Mirage drive.

That should keep me busy for awhile. I'm hoping to get the amas done soon so I can still enjoy them while the weather is nice.

Gary Lepak
Port Angeles, WA, USA
August 3, 2006

More articles by Gary Lepak:

Email this page to a friend