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Friday, September 10, 2010
LESSONS FROM A HURRICANE: AN ANTI SAIL DROGUE
While I was preparing for Hurricane Earl checking the lockers for "needful things" I might use in preparation for the storm. I came across something than was on board when I bought BIANKA. It was a surplus military "sea anchor" made in 1957 according to the markings stenciled on it. It was only about 3 feet around and I wondered what one of the previous owners had used it for. It did not look like it would hold up as a sea anchor or drogue in a rough sea. But, it looked like it would be useful as I prepared the boat for the arrival of Hurricane Earl. It was. In my research I came upon the concept of an anti sail drogue. BIANKA with it's cat boat design can fishtail or "sail" at anchor pretty far while at a windy anchorage. Anything I could do to minimize this would be helpful especially in storm conditions. So I turned this surplus military sea anchor into anti sail drogue. Here is what it looked like completed on deck:
This is how I rigged it. First I took some 1 inch webbing ran it through a five pound dive weight and stitched a loop on each end so I could attach a line to it. I then ran the line up though the drogue and attached it to the drogues parachute cord attachment point.
I then ran this line through the bow roller and cleated to the deck. The anti sail drogue should be about three or four feet below the surface. So I marked that on the line with red electrical tape and a red tie wrap as shown below:
And here's a view of it deployed off the bow::
The markings are good to have in case you have to lift it and redeploy it without trying to guess in storm conditions if it is at the right depth. Finally here is the antisail drogue in action off the bow:
I must say it worked pretty good. It did not stop all the fishtailing but, it certainly minimized it. I think an added benefit could be if the anchor started dragging the drogue would fill and slow down the drag perhaps enough to allow the anchor to reset. But, I hope to never have to find out if that hunch works. Now that I've made the anti sail drogue I have it ready to deploy if BIANKA needs to ride out another storm or even just in a windy anchorage to stop or minimize any fishtailing that happens.