• If you are citizen of an European Union member nation, you may not use this service unless you are at least 16 years old.

  • You already know Dokkio is an AI-powered assistant to organize & manage your digital files & messages. Very soon, Dokkio will support Outlook as well as One Drive. Check it out today!

View
 

Dan's 21' Ulua

This version was saved 15 years, 3 months ago View current version     Page history
Saved by PBworks
on December 19, 2008 at 3:05:10 pm
 
 Adventures with Outriggers
 
By Dan St. Gean - Chicago, Illinois - USA
 
I wrote an article for Duckworks Magazine a while back outlining a multipurpose sailing and paddling boat that I thought would work for me. The objective was to build a 21’ outrigger canoe as a paddle craft with a single outrigger. Part two of the article was to make a sailing trimaran with a second set of crossbeams with a second float.
The final part of the plan I never completed was to make a catamaran for cruising with friends. I bought plans from Gary Dierking for his 18’ Ulua. This boat also has the ability to scale up nicely all the way to 27’ long if desired. He also included plans for a trimaran style of crossbeam. This is where I got off track.
I regularly use my father-in-law’s Hobie Wave. It is just over 13’ long and sports 98 square feet of sail. I thought my new outrigger should have more than that. I had a sail maker draw up and cut a 128 square foot sail. The foot of the sail is 11’ in length (bottom of the sail) to clear the long cockpit. It is a leg o’ mutton style with generous roach and a big reef point. It is also tanbark in color and beautiful!
This is NOT the sail that Gary Dierking specified. Can you see trouble over the horizon? Designers, believe it or not, actually have some reasons why they specify what they draw. I knew that. I also thought I knew better. For example, Holopuni is a production Hawaiian sailing canoe. Holopuni models use a 100 square feet of sail. The same sail area is used by the Hawaiian Sailing Canoe Association on their racing canoes.
I scaled up the amas to an 8” diameter at their largest point and made them longer at 16’. Hopefully, they would stand up to my bigger sail without turning into submarines. I got the crossbeam dimensions from DGS Watersports, who build racing canoes. Cool stuff and helpful guys.
I didn’t ask DGS about the float volume—big mistake. Another mistake was the mast I made ended up way too heavy. One error was picking up an aluminum tube that was double the wall thickness of what it was supposed to be. The one I got was 12’x .250” instead of either .156” or .188” max wall thickness. I also used bird’s mouth construction for the upper section using ¾” thick Douglas Fir. I did taper the staves on the table saw, which is a potentially dangerous and scary operation since the staves were 14’ long. Long story short—the mast is too heavy for easy stepping. The mast must be 40-50 lbs.
When all that weight was piled onto the canoe with an 18” overall beam and an 18’ waterline, my freeboard quickly disappeared. Two 200+ pound guys aboard didn’t help either. Both floats weren’t planted in the water, but it was close.
I found that the freestanding mast was plenty capable of supporting the 128 square feet of sail, but the hull wasn’t designed for that much torque and twisted a bunch in gusts. Stepping the heavier mast was a back breaker too. The lake where I usually sail has a rocky shoreline. I need to step the mast while afloat or standing on the dock with the bow jammed under it. Not a good time to have passing powerboats creating wakes! After nearly killing both myself and the boat, stepping that mast, I found I was looking into carbon fiber masts.
Additionally, the larger floats weren’t large enough. They tended to bury once the boat was just starting to get going the speeds multihulls are capable of running. This is especially true on the wind when flipping forces are highest. Running was much better. Keeping a course paddle steering Hawaiian style was a huge challenge with my inexperience and regular canoe paddle. Experienced Hawaiian steersman use huge, oversized, and massively strong paddles. Now I know why. The S shaped wake we would leave behind from the occasional, accidental jibe was pretty funny looking. On top of that, I couldn’t hike out to counter the burying of the floats since I was paddle steering and confined to the aft seat “poking” the steering paddle.
It all added up to a boat that looked quite beautiful and functional, but did not perform as hoped. Designers, experienced sailors, and folks with a bit of common sense shake their heads and mutter. I realized changes must be made. The canoe’s low freeboard was first on the list of things to fix. It tended to swamp when slicing through boat wakes with the typical load aboard. Bailing and paddle steering aren’t a good mix.
I contacted Gary Dierking about possible solutions. My idiotic changes to a beautiful and functional design didn’t make him too happy. He did suggest some solutions that would work. Adding the raised cockpit would work to eliminate the swamping tendency. Larger floats would eliminate the submarine impersonations by my first floats. I remembered how hard it was to get fair floats with the surfboard construction style. This made me seriously think about sailing reefed all the time and call it good.
About this time, Gary was writing a book about building canoes. He asked for some pictures of the Ulua canoe I had built. I was happy to agree to it. He sent some pictures of other canoes that had been built to the design. I completely changed my thinking once I saw those images. I was not going to butcher the beautiful lines of Gary’s Ulua design by adding a box on top! Instead, I was going to go back to the design as intended. Designers, experienced sailors, and folks with a bit of common sense nod their heads and sigh with relief.
Instead of building an addition (more weight) to the canoe, I would build light crossbeams and use just one float that I had already. This is how the Hawaiians intended it anyhow. I might even have a sail built to Gary’s design and use a carbon windsurfer mast to keep things light. Basically I’m going to convert the boat back to the original Ulua stretched to 21’. That modification actually carried the designer’s go ahead.
So, this question loomed large… What should I do with all those carefully crafted parts and pieces from the trimaran attempt? The answer to that question will have to come in part three of the story.
Dan St. Gean

 

 

I've added some photos which aren't necessarily in order.  I built the hull at 21' with the trimaran/double outrigger akas first and found that I didn't like some of the double outrigger handling characteristics.  It was tough to paddle straight, flopped back and forth from ama to ama in motorboat chop creating splashes from the amas.  The amas were a bit undersized for the big rig as well.  I saw a Holopuni up close and realized their 14' amas are huge!  My crossbeams are up to the challenge, but the amas need to be bigger for the big rig.  Going to the single outrigger even with the same floats really helped.  I built the akas lighter with 4 of the 7 laminations out of WRC instead of Doug fir.  Plus they were 8' instead of 14'.  I like the way it sails and paddles now, but with two paddlers and cruising gear I was still skeptical if it was up to the Texas 200 challenge.  I took a Hobie 18 instead.  I did realize though that the H 18 was the wettest possible machine and am now looking to make a cruising catamaran using that rig.  At this point I'm considering another Ulua but with greater freeboard and decked over like Gary's Tamanu and altering mine to match, or just build a pair of Tamanu hulls.  It's hard to have too manu outrigger canoes you know.

 

Dan

Comments (0)

You don't have permission to comment on this page.