Sea Anchors

[Sonosailor]

This topic was obvious in it's absence under this listing. I know we have discussed these products elsewhere, but I could not find it.

We bought a sea anchor from Parasail, a 15 footer for our 35' catamaran, and rigged it for our trip from Newport to Bermuda and Bermuda to BVI. Didn't need it, but enjoyed the feeling of having it rigged and ready.

Newfound friends we met in Bermuda, Al Mosher and Michelle Stevens from Lunenberg, NS (Michelle runs a sail loft there), had purchased the same brand (either 15' or 18') and actually had to deploy it from Lunenberg to Bermuda on a 36' CS.

They rigged theirs with the appropriate recovery buoy and a chain in front to decrease strains and jerks. It worked beautifully for 2 days or so. When they went to recover it, and could not easily pull it in at the bow, they released it and circled back to the recovery buoy. However, the extra weight of the chain, without the extra support at the bow-end, sunk it.

Interestingly, the units were sold with instructions to include substantial chain in the rhode, but the manufacturers now suggest that little or no chain is really needed if good, elastic nylon is used. Mine is rigged without chain.

Al and Michelle were so happy with the system, that they ordered and received a replacement before going on to BVI.

Any other experiences or opinions regarding sea anchors?

[GordMay]

Excerpted from ”Heaving-to - Heavy Weather Sailing” by George Day

Lying To A Sea Anchor:

The technology of sea anchors goes back to the last century when fishermen developed sturdy canvas cones, with iron hoops at the mouth, for use when lying offshore in a storm. The sea anchors on the market today, most notably those designed and built by Dan Shewmon, are evolutions of the early canvass style. Relying on the conical shape to trap sea water,the anchor grips the water just under the surface and provides the drag needed to hold the bow of the boat to windward.

A traditional sea anchor needs to be quite large to hold the weight and windage of a larger, ocean sailing boat. It should be attached to the boat with a long length of anchor rode and, like the Gale Rider, should be fitted with at least one swivel to prevent the rode from kinking. The rode should be well protected from chafe.

An alternative to the traditional sea anchor is the para-anchor, which is a huge, lightweight sea anchor designed along the lines of a parachute. Para-anchors are sewn of heavy nylon fabric and reinforced with nylon webbing. The anchor is usually set from the bow, and like a sea anchor, should be fitted with swivels and plenty of chafing gear.

Deploying a sea anchor or para-anchor can be difficult, for it will be caught and tossed about by the wind and will take some time to open and fill once in the water. The rode should be played out long enough to place the anchor two wave crests to windward of you and should be adjusted to account for changes in the wave patterns.

The danger in lying to a sea anchor or para-anchor is sliding backwards as a breaking sea rolls under the bow of the boat. The hull slips back on the wave and the entire weight of the hull will fall onto the rudder. If the rudder turns as the boat goes astern, the pressure can easily bend the rudder post or shear off even the most robust pintels and gudgeons.

Experience will tell you quite quickly if the drift of the sea anchor and the size of the waves make lying to the anchor an unsafe proposition. In most seas and on most boats a sea anchor will be a useful storm tool. But it should be used with caution and a ready willingness to try another approach should backing on the rudder become a problem.

by George Day

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Additional resources:
“Venturesome Voyages of Captain Voss”
http://www.geocities.com/nelstomlins....appendix.html

" Heavy Weather Tactics - Using Sea Anchors and Drogues" ~ by Earl Hinz
"Drag Device Data Book" ~ by Victor Shane
"The Sea Anchor and Drogue Handbook" ~ by Dan Shewmon.