Trilibrium Approach
Excerpt taken from "More on storm tactics--balance, comfort,
 & Fiorentino's Trilibrium approach" October 2000 issue of
Blue Water Sailing.  By Zack Smith

...."Three factors that effect the equilibrium between your boat and a para-anchor are accurately defined by Fiorentino as the "Trilibrium Factors." They include 1) Sail trim; 2) Rudder Positioning; and 3) Rode Length. Familiarity with your boat makes sail and rudder trim straightforward. For example, as a gale intensifies, the bow of a fin-keel sloop normally starts to fall off the wind. In such instances, reducing sail forward to control leeward movement is an obvious opening tactic. If you're still having trouble achieving a comfortable balance, the next step is to hold the bow up with rudder angle, by steering more to windward. If this doesn't do it, and as sea state changes, a third adjustable factor--anchor rode length--comes into play.

Anchor rode length plays a huge role in the maintenance of harmony between your boat and parachute during deployment in heavy weather. Dashew provides data on "wave particle rotation" and the theory of "two wave-lengths between boat and drag device." Tests conducted by Fiorentino in heavy weather reveal that para-anchors and boats don't necessarily obey theories; in my experience, that's what makes sailing so adventurous. You have to feel your way through a rode-length problem. For example, if the bow of a vessel starts jerking or feels like it's being pulled through the waves, chances are that more rode needs to be deployed. If the boat feels like it is heading beam to the seas, even after adjusting sail and rudder, some rode needs to be retrieved because there's too much slack in the system. Excessive slack in the parachute system can be avoided by deploying small portions of rode at a time.

This brings to mind the last gale in which I set a para-anchor, including the deployment of 50 feet of anchor rode from a Catalina 30. Winds were a steady 35 knots, with gusts up to 45 knots, and 15-foot swells with occasional breaking tops. I paid out a small portion of rode at a time and secured it to a cleat. When the boat felt solid and comfortable, I could relax; when the bow began to feel bumpy, I paid out more rode. During the test, my anchor rode tethered to the para-anchor was taut. Adding weight to the anchor rode aided in keeping it taut while reducing shock loads to the boat. I've learned to place six feet of chain near the para-anchor whenever I suspect that wind forces may reach storm force.

Another point Dashew raises involves the notion that a boat apt to sail on the hook tends to sail more on a parachute anchoring system too. However, research by Fiorentino demonstrates no consistent pattern to support this theory. If your boat sails on a para-anchor, reducing sail area should correct the movement; if the boat continues to sail forward, consider rigging a bridle to keep your boat in a hove to position. While you may experience some forward motion on your boat when hove to during extreme weather conditions, this action is still your best choice.

Some forward motion is okay as long as this is counteracted by as much or more leeward drift. If the boat is moving slightly ahead, I've never found it necessary to reduce sail. If I begin sailing forward too much, I do notice that my taut anchor rode will sit next to the boat with the para-anchor off my stern quarter. This I take as a hint to reduce sail. Heaving to doesn't take much to master and has solved the problems of sailing at anchor in over 90 storm tests conducted by Fiorentino in monohull sailboats.

If you decide to run a para-anchor straight off the bow of your boat, consider using weight on the anchor line to keep it taut. Also consider using spring lines to absorb rogue waves or disturbed wave patterns coming from more than one direction. A spring line dampens any sudden surges placed on your boat. Balancing a boat to avoid the issues that Mr. Dashew raises in his article takes only reasonable practice and common sense."

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