by GreenLake » Mon Oct 08, 2012 1:35 pm
Back to spinnakers:
When you add a symmetric spinnaker, you'll need 5 lines and a pole.
The spinnaker halyard and the two sheets are somewhat similar to the same lines on a jib. However, the difference is that there's no "tack" on the spinnaker, so no corner of it is tied down to the boat, and instead of both sheets leading off the clew as in a jib, each sheet goes to it's own bottom corner of the spinnaker. The sheets also run outside all the stays and are sheeted from points near the stern of the boat - that's why the sheets have to have twice the length of the boat (plus a bit).
In light winds, and heading nearly downwind, you can fly a spinnaker with just these three lines. The spinnaker will balloon in front of the forestay, and you control each corner of it with its own sheet.
If you add a spinnaker pole, you can push the sail out to one side, so it comes out of the wind shadow of the main. Initially, there's not a huge difference between a whisker pole and a spinnaker pole. However, especially in light winds, the spinnaker pole may be too heavy and would drag down the sail, if you didn't support it. Hence the addition of a topping lift for it (for small boats, this is tied to the middle of the pole, for larger boats you need a bridle, or you'll bend the pole).
In stronger winds, you have the opposite problem. The spinnaker isn't tied to the bottom of the boat, like a jib, so nothing prevents it from "skying". So, you add a downhaul (or foreguy) to the spinnaker pole. Between these two, topping lift and downhaul, you can set the angle of the spinnaker pole, that is raise or lower it, until you have it where you want it - usually horizontal.
Having to adjust two lines to get one result can be annoying. For a smaller boat, like the DS, it's possible to replace one of the two lines by a bungee (or a line with a short piece of bungee spliced in). That way, you can adjust the opposing line and the bungee pulls the pole into position.
Mine is currently rigged with a bungee in the topping lift, in his rigging guide Phill describes his setup which has a bungee in the foreguy.
Once you've rigged your pole, you pull on the windward sheet to position the pole at 90 degrees to the wind. (To make matters totally incomprehensible to the uninitiated, the sheet that's attached to the same corner of the sail as the pole is called a "guy", as "guys" are the lines that control the pole, while "sheets" are the lines that control the cloth. So your windward sheet is always the "guy").
With a pole, you can go nearly to a broad reach (at which point the wind comes from the side and the pole is as far forward as it will go, touching the forestay).
For casual sailing, a symmetric spinnaker wouldn't be my first choice - it takes a bit to get the hang of it and it's definitely temperamental. In moderate conditions it's possible to do it single-handed. It takes about one sailing season to get the hang of the basic operation. If you get an old spinnaker for cheap, or even free, and like puzzling your way through the rigging and running of it, why not.
Otherwise, if you have the money for the upgrade, rig a UPS. (See thread on that). That will operate more like a jib, and give you additional power in more upwind course, where you can't fly a spinnaker at all. But that's getting into another topic.
As this thread is (more or less) about rigging a spinnaker I've not addressed the in's and out's of flying it (and how to gybe one). I've found that it's nearly impossible to get that across in a description, but having seen it (and done it) a few times it all comes together.
~ green ~ lake ~ ~