Kevin Wensley: Hello! My name is Kevin Wensley. I am Director of Operations at Offshore Sailing School, and today, I am at South Seas Island Resort on beautiful Captiva Island here in Florida. And today I want to talk a little bit about anchoring. Assuming you know where you want to go to anchor, there are a few things you can consider along before you get there.
The first thing is going to be, I want to be in the lee of the land, I want to get some protection from the wind. I also don't want to be in too much current. So you can have a look at your chart and you can also have a listen to the weather forecast to find out where the prevailing winds are going to be to see if you can't find a couple of spots that will be suitable for stopping into.
The next thing you want to think about is, what's the nature of the seabed, when I get there, is it going to be grassy, is it going to be sandy, is it going to be rocky, so have a look at your chart, see what it says about the nature of the seabed and it will highlight things like coral which of course we should never anchor in.
So once we have established where we think we want to be, it's time to head over towards the anchors. The next step is to think about how much anchor line or chain you are going to have to pay out. So to do that you need to factor in three things. One is, you need to know the water depth as it is now, and you will get that from your depth sounder so let's say it's 10 feet.
The next thing to factor in is how much more water will that be if the tide comes in while you are staying that for the evening. So if we take the tide table and it says there is going to be another three feet of tide, and we are in 10 feet of water right now, then we are dealing with 13 feet so far, but we also have to factor in the distance from the stem fitting down to the water line or the free board of the bow. So let's say that's another 5 feet. So we are looking at 18 feet as a distance from the stem fitting down to the seabed.
Then we want to consider scope, and scope is the number by which we multiply that 18 by to come up with the amount of chain or line to pay out. If we are working with just line, just line-on-line, then you can use a ratio of say 7:1, if it's all chain, then you can get-away with maybe 5:1, and if you are just stopping for lunch, maybe you can get-away with 4:1.
So let's say we are working with old chain, so we've got a distance of 18 and a multiplier of 5 so that means we need to be paying out about 90 feet of chain.
The next thing we want to do is have the driver bring the boat to the point where we want to know the anchor and have the bow pointing into the wind. Once the bow is into the wind and the boat is stopped then it's okay to stop paying out the chain. And we can do this either by pressing the down button the windlass or perhaps releasing the brake which would allow the chain to go out more rapidly.
The important thing is though that we don't just pay out all the chain and play it on top of the anchor. What we need to do is as the boat is moving backwards with the wind, allow the chain to pay out and once we paid out to our 90 feet of chain, it's now time to set the anchor. The way we do that is we use the engine to back down on it, so we are looking to back down at about 500 RPMs.
The other thing we want to do is, we don't want to overload the windlass, so it's good if we can transfer the load to a cleat that's nearby. So tie a short piece of line around the chain, attach it to the cleat and then go ahead and back down on your windlass very slowly increasing RPMs to about 1500.
If we can back down at 1500 RPMs and the boat isn't moving backwards, we can be confident the flukes are buried and the boat is in a secured position for the duration, and that's the basics of anchoring when we are cruising.