Mizzen (yawl) as a self steering system

[Owly055]

I've been following David Omick's blog for awhile now.  https://omick.net/adventure/mizzen_self_steering/mizzen_self_steering.html

A doer and an adventurer,  I admire his intrepid adventures and willingness to dive right in and do things.   A Some of his adventures with his wife involve sailing long distances in very small boats.   His latest project has been to build a small catamaran of his own design. Unique in construction and various design features, built with the "instant boat" methods similar to stitch and glue.  Open deck, 23'9" long and 13'4" wide,  it is built to be strong and simple and to carry him and his wife to the pacific islands in "minimal style".... a voyaging sea camper I would call it.   What a way to travel....... intimate with the sea rather than high above and looking down at it.   The boat is unique in it's 4 mast junk rig among other things.  A biplane schooner rig.   If four masts at first seems like a handful, that thought is quickly dispelled when you think about the small size of each rig, the short masts, the lack of any standing rigging, the fact that a junk rig reefs instantly on any point of sail by merely releasing the halyard and dropping the sail into the lazy jacks where the weight of the battens makes it unnecessary to tie in reefs, and the fact that tacking involves nothing more than putting the tiller over and letting the sails swing across, then adjusting the sheets if needed.  Even with 4 sails it will be far simpler and easier to sail than a typical sloop of cutter.  The short mast height is an asset in many ways.......... just not maximum performance, but the instant reefing allows you to safely carry a lot more canvas.  The boat is designed to carry all the supplies for two people for the intended passage across the Pacific with a good safety margin.   The boat is sensibly designed with dory hulls to maximize usable space in the hulls, and load capacity.

One of the main ideas of this was to make a boat that would self steer just by setting the sails properly.......... and in sea trials so far it has worked fine.   In addition David has designed a self steering system that will use one mizzen depending on the tack. 


He has a great series of Utubes of his Windrose sailing in Lake Roosevelt in Az. with a yawl mizzen rigged to act as a windvane steering system... a simple well thought out system.  The rig on this mizzen is what he calls a "Lateen Junk Rig", which basically is the top 2 panels of a high peaked junk rig with the battens all connected at the forward end  such that multi part sheets are not needed.   He sheets to either side of the boom, running through blocks to the tiller via a cross bar on the mast. 
     It has multiple advantages, low cost and simplicity being high on the list.  It also can be set as a riding sail so the boat doesn't sail on anchor, or to help balance the helm, or anything else a yawl mizzen is used for.


It makes a good read.   I'm hoping to see the boat in person in Sept or Oct, as I'm heading that general direction (I hope), though I'm questioning weather I should visit my mother (89) during this outbreak of delta.  Though she's been vaxxed as all intelligent people have by now, I don't trust the immunity against delta, as immunity seems to wane.   Fortunately she is very healthy, having been blessed as all members of my family have, with a very strong immune system and constitution. 

                                                                                                                                                           H.W.

[Owly055]

Just to add a bit more to this.........  I've long looked for accounts for a yawl mizzen being used for self steering, and have found only one account, involving a fellow in New  England who added one to a dinghy for that purpose, basically using it to balance the boat so it would stay on course.  It worked according to his written account of it.     Joshua Slocum added a yawl mizzen to  Spray in South America during his round the world voyage.  I've long suspected it had a lot to do with self steering, but in his book, he made zero mention of why he installed it or how he used it.  It could not have been much use as a driving sail, nor did he spend a lot of time at anchor, so I doubt that his primary use was a riding sail, so obviously it had to be for balance, which suggests that it was to improve the self steering.
                                                                                                        H.W.

[Frank]

Glad your mom’s healthy! Crazy times..
Have you settled in on a boat yet or still looking at options?

[Owly055]

Glad your mom’s healthy! Crazy times..
Have you settled in on a boat yet or still looking at options?

I pretty much know what I want...... I also know what I can afford, and there's a divergence there.    A multihull is a non-negotiable, and unfortunately it will have to be larger than I would like due to payload, which is important for the kind of sailing I plan to do.   Not for conveniences etc, but for supplies, tools, and spares.  The idea is to have the smallest lightest catamaran that is capable of carrying a reasonable payload.      That means it will end up being in the low to mid 30's.   I've looked at trimarans such as the Searunners, but they have half the payload for length.  The smallest catamran design that would work for me would be about 30', but most 30 footers are designed for performance.   To get what I want I almost have to build to order, but I'm not willing to do that.    A bridge deck cabin or pod with good shelter and all around view is important.... but it would not have to have standing headroom.  The Edel Cat would work for example but I don't like the bridge deck clearance.  Richard Woods Sagitta would be perfect if the hulls were reworked for a bit more displacement...... but again, I don't want to build.   A Wharram with a pod would be a reasonable choice, but far from the top of my list.    I have a model of my ideal catamaran on my desktop.  Like Davids Minimus II it would has a flat bottom, a transom stern, and a biplane junk rig.  It has a bridge deck cabin that integrates with the Stbd hull, and stops short of the port hull leaving a walkway fore and aft, and like the FP Maldives, it has a "pop top"......... As with most things, I will settle for less than what I want.... which actually will probably be more than I want ;-)