Being blown off your anchor is frightening. It seems that babies and bad storms all come at 3 AM, so if your anchor drags, you'll be drifting towards shore, while trying to get the sleep out of your brain at 3 AM, in the dark, in a storm.
Having been blown off our anchor twice in our previous boat (the anchor was appropriately sized for the boat, but it was too light to really bite into the bottom), I have a healthy fear of this prospect. And when we hauled our anchor up in Port Madison after a calm night and found that it was embedded in a tangled ball of chain, that fear arose again. Since it had been a quiet nite, there was no problem... but we had been anchored to a pile of chain - not an anchor.
One way to make sure that it doesn't happen is to be moving backward when the anchor kisses the bottom. You see, if you are stationary, then the anchor hits the bottom and immediately gets a pile of chain deposited on it. Generally this will foul it in some way, and you'll have one of those situations where you depend on something to be trustworthy, but when push comes to shove (or pull), it lets go, at the worst possible moment.
And it took quite a while, hanging off the bowsprit with the boathook, to untangle things. Thankfully, that was the worst of the problems.
- Always have the boat moving astern when the anchor touches down. We now have a system - Jane waves to me from the bow when we have veered enough chain to reach the bottom. I need to have the boat moving astern by then.
- Always be sure that the anchor is well and truly hooked. The rode should come taut with the sternward motion.
- Do not leave the boat unless you are certain that the anchor is hooked. This seems like a silly, obvious thing to say, but we have seen more than one captain drop the hook, jump in the dinghy and head for shore before the boat had hardly stopped moving. On at least two such occasions, the boat was not hooked, and ended up drifting down the anchorage, collecting insurance claims, like seaweed on a drift log.
Years ago when I was a kid, I used to read Flying magazine. I particularly enjoyed a long-running series of articles entitled "I Learned About Flying From That." Each article was written by a pilot, who humbly admitted to having made a mistake, and then having lived, told about it in the hopes that others would not have to make the same mistake. I thought then that it was a good format, and I still think that now. This series of postings is my attempt to recreate that article series with a new subject and new technology.
(If you would like to help others to learn from your mistakes, please send your article to: WindborneInPugetSound at gmail dot com)