One picture is worth a thousand words. The Paine DVT work beautifully. There are expensive and unsightly alternatives, but this solution is cheap and attractive. Because they are parallel with the luff, they permit the use of a roller-furling jib, which would not be the case with conventional battens.
This shows how they work on a close reach. Note that the leech of the jib is nearly parallel with the luff. Without the DVT the jibboom would move up as it is let out, but as you see here, the DVT force it to stay low and rotate sideways, not vertically.
The DVT are at their most effective the further you let the jib out. Usually in these wing on wing situations the jibboom rises up in the air, spilling wind from the top of the jib. With the DVT this does not happen, and the entire jib remains effective.
Yesterday I tried out my invention- the “Paine DVT”, for the first time. They work splendidly! They consist of long fiberglass battens that extend all the way from the leech to the foot of the jib. Just as predicted, they prevent the jib-boom lifting and spilling wind from the upper parts of the jib. When you let the jibsheet out, the jib goes OUT, not UP as is the case without the DVT.
The PAINE DVT are those parallel stripes in the jib.
A few years ago I invented the Paine DVT for use on my PAINE 26. (Stands for Dang Vang Thangs). The idea is to find an alternative to the Hoyt Jib Boom for jib vanging. Especially with boomed jibs, when you let the sheet out, the jib does not go out, but up- with the result that the whole top of the jib becomes ineffective. The Hoyt boom works beautifully, but is expensive, ugly, and a huge impediment to being on the foredeck, even when the jib is furled. My DVT are a series of stiff battens that run parallel to the headstay. Their top ends act as battens to flatten the leech of the jib. But it is my hope and expectation that they will effectively prevent the clew of the jib rising up as the sheet is eased. Well, I’m now into the experimental stage, and am fitting the company PAINE 14 demonstrator with the DVT, and will let you know in one week how they work out. Fingers crossed!