Anchoring—Safety First … ALWAYS
by Brian Brown
Scope, slope, chain, line…all can seem pretty frustrating to figure out, but when you add in terrain (the sea bed floor), wind and current and the fact there’s no anchor that can handle every anchoring situation, you’ve got to be super careful where you drop your “hook”. You don’t want to find yourself a drift while you’re asleep…running into “surprise things” can be very scary; especially at nite and while in a deep sleep. Word of advice here: anchoring in a calm protected can be quite different than anchoring offshore or on a large open bay. Don’t forget the weather–high winds, tides and waves can all make anchoring difficult, if not impossible.
Here’s a scenario you want to avoid…but can happen: It’s a pitch-black, nasty night with rain blowing sideways, and your concern about your anchor dragging sends you topside again to shoot bearings through lightning on distant landmarks. You escape below only to have your pencil tear a hole in the soaking-wet chart while triangulating the boat’s position…but there are electronic options, discussed below.
First, all the basic equipment surrounding the anchor is called “ground tackle”. This includes an anchor, chain, line and connecting elements. The anchor line, including chain, is called the rode.
Next, your boats size, weight, design and bunch of other elements determine what type of anchor you will need. For instance, a 30 foot 10,000 pound houseboat needs a larger anchor than a 30 foot 10,000 pound sailboat.
Here’s a chart you might consider using:
OK, let’s get back to the discussion of SCOPE. It’s somewhat scientific; but remember that wind, current and the bottom surface all play a very important part in this discussion. To establish the right scope you will need to determine how much anchor line, or “rode”, you will need. It is recommended that you use a scope of 7:1, meaning that for every foot of water depth, you should use 7 feet of rode. Scope=A/B
A=the rode length and B=the depth from your cleat where you’ll tie off (or windlass).
For example to anchor in ten feet of water you need 70 feet of line. Here’s another chart that will help:
Now, the next part is so very important. STAYING PUT!
It’s best to take immediate bearings once your hook has grabbed. Take two visuals, look at points on the shore, and take note. Those points could be a flashing beacon, or a high rise building, or just a dip in the horizon. Keep your eye on that point for a while to make sure you’re not dragging the anchor. But another way to check and see if your anchor is set properly is just to put your hand on the line. If the line is “vibrating” and not solidly taunt, then you are dragging your anchor and you have not properly set your hook.
If you’re into using electronics there are many apps for anchoring. NAV-X AND Drag Queen are the ones I use. Yes, you read right, Drag Queen. I run NAV-X on my ipod (in a waterproof case) and Drag Queen on my iphone.
Anchor types…best to discuss with your boat maker (or a knowledgeable person) before buying. Lightweight ones are Danforth. They are primarily used for recreational boats. Kedge of Navy Anchors, the traditional style of anchor, generally used for very large ships, it relies on weight for holding power. Grapnels Anchors, very inexpensive but little holding power.
Plow or CQR/DELTA Anchors, looks just like an old fashioned plow. Very good holding power. Claw or “BRUCE” Anchors, unique shape of the claw allows a 360 degree turn without breaking out. Has similar performance to plow anchors, at a lower weight. Mushroom Anchors, used for moorings, and small boats but not for large ones. Buoys and beacons have Mushroom Anchors.
Straight chain is better than a combination of chain and line but if you want to use line because it’s lighter and easier to haul, then don’t scrimp on it. Get a very good quality. If you’re going to use line, use at least 10-15’’ of chain connected to the line/anchor.
Another BIG tip: SPRAY PAINT (IN NEON) ON THE LINE EVERY TEN FEET so you know how much line you are letting out. One mark for up to 50’ and then two marks to 100’ and three marks at 150’.
Last, make sure your crew knows how to avoid the pitfalls of launching an anchor, even if you think it’s the most simple thing. If, for example, your crew’s foot is accidentally wrapped around the line when they throw the hook over, they could go with it.
After about a third of the line you need is out, give the anchor a tug to see if it’s set.
WATCH OUT WHEN YOU GO TO CLEAT THE ANCHOR LINE AFTER YOU’VE THROWN IT OVERBOARD, BECAUSE THERE’S USUALLY A LOT OF TENSION ON THE LINE AND FINGERS CAN GET SMUSHED. As a Captain you have the responsibility to show your crew how to use the cleat to slow the line down from running, without burning their hands or fingers. The best way is to put half a wrap around the cleat immediately after you toss the anchor…
Last, poor communication between the Captain and the crew on the foredeck can get someone hurt. It’s much harder to hear when you’re the crew and the Captain is at the wheel, so it might help to have a relay person mid-deck to relay the communication between the Captain and the Crew.
Safety first, and dropping an anchor, while seemingly simple, can be a dangerous event if the crew is not properly trained. And, by the way, I am out of words for this article, but hauling the anchor requires special training too.