anchor v. sea anchor

[C-Trial]

I'm trying to understand whether to purchase a sea anchor. For those reading this, the type of sea anchor would be something like the 9' Para-Tech to be deployed at the bow in open water and heavy seas when it is not possible to run for shelter.

If the purpose of a sea anchor is to create the open water equivalent of a mooring buoy that lets the dory literally ride out heavy water in emergency conditions, why not (if depth permits) simply drop anchor of the iron variety with sufficient scope to get a bite on the bottom?

Dory's, I suspect, by virtue of their size would seldom venture out into blue water (S. California and Alaskan cruisers excepted). Offshore Oregon and in the Puget Sound/Canadian islands where we are, the water for the most part isn't really that deep to preclude dropping anchor.

Is the problem with dropping anchor (versus deploying a sea anchor) that the rough water might tend to jerk a bottom anchor loose? With sensible scope and the shock absorbtion of nylon rode I'm not sure i see the difference in safety?

Thanks,

C-Trial

[KenMcC]

Hi, C-Trial,

The primary advantage of a sea anchor is if you lose power in a blow. It'll keep the bow headed into the weather and prevent a possible swamping. They're mostly used where the water is too deep to drop anchor. They can slow the rate of drift considerably, but you don't want to use one anywhere near a lee shore. Under those circumstances, dropping the iron is the best bet.

Chapman Piloting, Seamanship, and Small Boat Handling has quite a bit of information on sea anchors, drogues, and how and when they are used.

Ken

[C-Hawk]

I have the sea anchor for emergency purposes. The rode on my sea anchor is 80'. The reason I want it our so far is to get it out at least 3 wave lengths in front of the boat. Any closer and it will jerk every time a wave lifts the bow.

[C-Trial]

Thank you, Ken. I should've thought to look in Chapman's.

Roger, out of curiosity, have you ever had reason to deploy? If yes, was the experience about like you expected?

John

[hmcarthur]

Whoa!!!!!

Never, never use a "ground hook" to retard drift in a strong current or strong wind with a scope of less than 8 to 1. Even then disaster can occur if the "lift" component of the bow is insufficient to overcome the "suck" effect of a securely attched grapple in a strong current.

The idea of "dragging" a ground hook in "deep" water in order to retard drift and assist in "heading up" is a recipe for disaster. Should the hook suddenly engage ANYTHING you run the risk of having the bow suddenly, and without warning, being sucked below the surface and the result is as you might imagine!!!! An entire family was suddenly lost off John's Pass in the Gulf of Mexico (Fla. West Coast) when their 23' vessel was instantly sucked beneath the surface while engaged in this exact error in judgement.

Sea anchors come in a variety of sizes and should be matched to the vessel. In an emergency a sea anchor should be deployed with sufficient rode length to allow the anchor to "fit between the waves" depending upon conditions. A sea anchor has saved many lives as it will keep a distressed vessel "headed up" without much "stress" on the bow.

There are "lunch hooks" for casual cruising in good conditions and where one will not lament if said hook is lost to coral etc. There are serious "storm hooks" which everyone should carry in extended cruising but these require considerable skill, as suggested above, when being deployed. Water depth, rode size, scope and bottom composition all must be measured carefully in the final equation.

Then there is the wonderful "Sea Anchor" which correctly used will either save the day or make the day much more comfortable until adverse conditions subside. Many a Mariner has hastily constructed their own sea anchor from anything they could bind together and drag off the bow - should this emergency develop it is not wise to use children, the dog or the Second Mate as an emergency device.

I was disturbed by some of the posting I saw on this topic - please factor all of the above into any decision to hang a hook off the bow, stern or gunnels of any moderate sized vessel that is moving!!

For the record, I have been a commerical pilot for years!

[C-Hawk]

Luckily- no. I've never had to employ in case of emergency. But it works great for a slow drift in wind for halibut.