
...."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."