Staysails are the smaller jib on a cutter. They are mounted to the inner forestay, which is the stay inboard of the headstay and attaches only partway up the mast. When tacking a cutter, you have the jib and staysail to sheet on each tack. This can become quite a chore when short tacking through narrow waterways.
To reduce the number of sheets that need to be adjusted, I have made the staysail self tacking. This lets me short tack up a narrow waterway, while only having to adjust the sheets of the jib (if I'm flying it). If it is a very narrow waterway, I will lower the jib and fly just the main and staysail, allowing me to short tack without having to adjust a single sheet. This lets me direct all of my focus to avoiding obstacles and other boat traffic while working to windward.
The reduced sail area does lower my speed, which is a good idea when sailing in crowded and cramped waters. If we were to collide with an obstacle, our slower speed will give us more time to react while lessening the damage of the collision.
Self tacking staysails are nothing new, but most require very complicated systems and hardware to work properly. There are a few requirements that must be met for a headsail to self tack:
The sail can not overlap the mast
The sheets must be free and clear of any deck hardware
The sail needs a clew block to allow for trimming twist from the sail (optional but very helpful)
If the sail overlaps the mast, any self tacking hardware would hit the mast on each tack. It simply would not work.
The sheets need to be free and clear of any deck hardware to avoid them getting hung up on said hardware. Also, laying on hardware can cause stress points that will lead to chafe on the line.
Some common self tacking systems include the Hoyt Boom which is used on Island Packets to make their staysail self tacking.
Booms are wonderful for sail control, which is why your mainsail has a boom under it. The problem with booms on the foredeck is they hurt when they smash into your shins! If your headsail is flogging around, so will the boom under it! The alternative is to negate the boom and instead mount a traveler on the foredeck ahead of the mast.
All these extra parts, in the form of booms or traveler tracks cost a fair amount to have made and installed on your yacht. There must be an easier way?
There is! Simply installing a block on the clew will convert your staysail into a self tacking staysail. The block runs on a bridle which allows the sail to slip from side to side as you change your tacks. If you get hit by the block while the sail is flogging, it doesn't hurt that bad (as long as you use a light weight block).
While this self tacking system is inexpensive, it is also less than perfect. The sail will have less than ideal sail shape while sailing to windward and significant twist when sailing off the wind. This is because the sail is sheeted onto a bridle. To help counteract the twist, I attach the block higher up on the clew block. This is effectively the same as moving the sheet blocks forward to apply more tension to the leech.
The first version of this system involved my old staysail which had a clew cringle and a very heavy block. The bridle was sheeted to the toe rail, fixed at one point with the other end running back to the cockpit. The principle concept was there, but it needed a lot of tweaking to get to its current state.
The theory was: "As the sheet is eased, the bridle will loosen and the clew can rise and fall off the wind towards the leeward side. As the sheet is brought in, the bridle will tighten and the clew will stay more midship. As you tack, the block would slide along the bridle to fall onto the other tack. Sheet control was simply bridle tension, the sail would always fall towards the leeward side." This worked, but the lead angles were so wide that I was never able to point very high with it; I simply was unable to sheet it in all the way. It was also a tripping hazard when walking forward on the deck. This led to the second version of the system.
The second version involved the new staysail which had a clew bock installed on it. The clew block allows for adjusting the lead angle on the sail instead of moving the lead blocks fore and aft. I also moved the bridle leads inboard to the staysail track. This version worked better to windward and I was able to remove some of the twist by attaching the block further up on the clew board. As you can see, the sail still cups at the clew and doesn't have the best of sail shape. For short tacking, this isn't such a big deal, but when on a long tack, this is lost efficiency.
This led to the third and current version of the self tacking staysail. The self tacking block is left attached to a higher hole on the clew block. On a lower hole, a standard sheet is attached to the staysail, allowing excellent sail trim and shape to be achieved on long tacks. The self tacker is also a very lightweight Carbo Harken block, further reducing the agony from getting hit by the block when the sail is flogging.
Development of the self tacker has finished, because I am pleased with where it has come to. While short tacking into or out of a harbor, I can set the self tacking sheet on the winch and work my way to windward. Once out of the harbor and into larger water ways, I can set the non-self tacking sheet on the winch and work my way towards my destination with perfect sail shape.
While the self tacker is not perfect, it only cost me a few blocks (three to be exact) to rig and is easy to convert back to a regular sheeting system if I were to require it. This was very important to me since I heave to during storm conditions and a self tacker will not allow the sail to be backed. The simple act of switching the sheet on the winch is all that is required to convert from self tacking to regular sheeting.
I use this on my staysail, but if you have a sloop rig, you can use this on your non-overlapping headsail to convert your regular jib into a self tacking jib for short handed tacks.