Location: Warderick Wells Cay, Exumas, Bahamas
Coordinates: 24° 23.689′ N 76° 37.950′ W
Since leaving the U.S. we have begun to anchor out more often than we moor at a marina. Anchoring is both easier on the budget, and more satisfying to the soul. However, it does not come without some concern for the security of the boat and the comfort of the crew. While I’m sure we still have a lot to learn, this entry describes some of the tools we use and lessons we’ve already learned.
We have two anchors aboard Three@Sea. Our primary anchor is a 75-pound “plow” anchor (CQR brand) with 300 feet of chain. This seems to be a great anchor: it sets quickly and allows for a wide swing angle without having to re-set. Our secondary anchor is an aluminum “danforth” with 24-inch flukes (Fortress brand), 40 feet of chain, and 250 feet of nylon line. The danforth anchor was designed to hold the landing-craft off the beach during the invasion of Normandy during WW-II, and it lives up to its design: this is a great sand anchor.
The main thing you are concerned about when anchoring is that your anchor will hold the boat in place. But even in this simple goal there are conflicting forces: A longer rode (chain and/or line) gives the anchor a better chance to hold because there is less force pulling “up”, and more force pulling “sideways”. However, the longer the rode, the wider the swinging range when the wind and/or current change. Many of the anchorages in the Bahamas have strong tidal currents, which change direction with the tidal cycles. So not only will you swing around on your anchor, but you will probably swing around 180 degrees, which may even cause your anchor to pull out backwards and have to re-set itself (which it may or may not do successfully every time). This is why somebody came up with the “Bahamian moor”.
A “Bahamian moor” uses two anchors, set at approximately 180 degrees from one another, in line with the expected current flow. When the tidal current is going one direction, the upstream anchor is active and the downstream anchor is slack; when the current switches around to the other direction, the opposite anchor takes over, leaving the previously working anchor slack. This has two main advantages. First, because each anchor is only pulling in one direction, they are likely to stay set (i.e., not pull out backwards or drag unexpectedly). Second, because the boat is connected to the end of each anchor rode where they meet halfway between the two anchors, the boat stays pretty much in one place, only rotating around the bow where it is connected to each anchor rode. This is very cool! While we won’t set a Bahamian moor every time we anchor (it’s definitely more work than setting one anchor), now that we’ve used it a couple times, I’m convinced of its usefulness.
How do we know whether we’re staying in one place or not? We use two tools for this. First, our GPS system has the ability to set an “anchor alarm”. Once it seems like our anchor is set (which is simply judgement), we set the anchor alarm on the GPS to tell us if we have moved more than, say 60 or 120 feet (i.e., 0.01 or 0.02 nautical miles). We usually put out about 75-100 feet or anchor rode, so this size alarm will tell if we have dragged significantly, or (if we’re not on a Bahamian moor) that we have swung around to the other side of our anchor. If the anchor alarm goes off, how do we know which it is (swung or dragged)? Well, we could look at a landmark on shore, or judge the distance from other boats around us. Unfortunately, both of these are pretty subjective, and very difficult to do on a moonless night at 3am. Enter the second tool.
Both of our navigation plotters have the ability to draw a “track” of where the boat has been (based on the GPS signal). While at anchor we can zoom in to the largest magnification, and we can actually see the path of our swinging boat being drawn on the plotter. Over several hours this looks like a big blob of scribbles, which makes it very easy to see if we move outside the normal area of movement. So when the anchor alarm goes off, we turn on the plotter screen and immediately see the nature of our movement. Pretty cool!
Okay, now that the boat is secure, how do we make it more comfortable? This really boils down to reducing pitch and roll as much as possible. The first and most important thing to achieve this goal is to select an anchorage that is well-protected from the prevailing wind and sea. We do this by looking at the geography of the proposed anchorage, and being aware of the weather and currents. Most of the time you want to be on the lee (downwind) side of some land, tucked up as close as possible to the land (but far enough away so that you can still swing on our anchor and not run aground). Once this is accomplished, there will still invariably be some waves in the anchorage. The waves that come straight into the bow of the boat aren’t too much of a problem: the boat pitches a little bit, but it’s not too uncomfortable. The real problem is the roll, which can make you feel sick over a period of hours. For this problem, we deploy a “flopper-stopper”.
A flopper-stopper is essentially a lever that you put out one side of the boat to resist the roll. (What’s the quote: ”Give me a long enough lever, and I can move the world!”) Our flopper-stopper is a 10-foot arm that sticks out the port side at about amidship. It has a chain that extends diagonally up to our stack, and a chain that hangs down into the water to attach to the “plate”. The plate is like a check valve: when it gets pulled up by the boat rolling right, it resists against the water; when it drops down by the boat rolling left, it lets water through and sinks quickly to keep the chain taught (making it ready to resist when the roll reverses). This doesn’t take all the roll out of the movement, but it helps a lot!
Of course, none of this would work at all if I didn’t have the best crew in the world: Kathryn and Ayla have become masterful at handling the anchors, making my job of maneuvering the boat much simpler during the anchoring and un-anchoring process. The process of setting and retrieving two anchors is not easy, and it requires all three of us to do it successfully. Eventually, I expect that we’ll even do it smoothly.