Monday, December 15, 2014

Dropping the Hook - Wrong Ways and Right Ways to Set Your Anchor

Anchoring: The Most Important Part of Boating

After purchasing our sailing catamaran, Unbound, out of a charter fleet in BVI, we spent many weeks enjoying the local fun and fare that the British Virgins have to offer. Our cruising carried us through the peak holiday season, between Christmas and New Year. We made shocking observation during that time - many boaters do not know how to properly anchor!

After observing this fact - charter boats dragging anchor everywhere, bumping into other charter boats and private yachts - we decided to watch the charter companies and their "checkout" process. We saw that the charter fleet captain would take a new charter guest on a sea trial, verifying that the captain knew enough to safely operate the charter boat. They would raise and lower sails, tack this way and that, start the engine, and use the VHF radio. Not once did we hear the clatter of a windlass, or see any mention of anchoring. In the BVI, charterers are encouraged to pick up one of the abundant public rental moorings.

Moorings in the BVI are great. There are lots of them in all the best hot spots and popular anchorages. That is until Christmas. It seems every boater and wannabe cruiser on the planet finds their way to the Caribbean for the holiday week. Available moorings are now scarce, and suitable anchorages fill up rapidly. This is where the fun begins. Overnight anchoring in the Caribbean is not the same as dropping your hook to have lunch off the Brewsters on a clear day in Boston Harbor.

During winter, Trade Winds blow pretty steadily and predictably throughout the Caribbean. At night, the winds change dramatically around mountainous islands. Differential cooling of the mountain slopes create lots of strong updrafts and downdrafts that translate to sometimes wildly shifting winds near shore. Improperly anchored yachts are at the mercy of these winds.


The Wrong Way

The "Dumper" (Very Common)

We have seen many boaters make this common error - dropping a pile of anchor chain or rode right on top of their anchor. Boaters simply place their bow over their chosen spot and dump anchor and chain. Sure, they have calculated how much chain or rode to lay out, and, hopefully, their rode is marked in some way so they know how much has been released. The problem with this method is that the pile of rode fouls the anchor, and chain may snag on an anchor fluke while the anchor is being set. This may hold for a while, but creates a dangerous opportunity for the anchor to trip, and likely have trouble resetting.

The "Short Story"

We have all seen this: A boater drops anchor and lets out just enough rode for the anchor to stop the boat from drifting. This is great in in 5 knots of wind from a windward shore. Not so great when the wind or tide shifts. The anchor will almost always trip and not reset.

The "Long Haul"

Some boaters are firm believers in the More is Better philosophy. They lay out lots of anchor rode - sometimes all of it - and create a problem for all the other boats in the anchorage. Keep in mind that the placement of your anchor roughly determines the center of a circle that your boat will swing in. You may think that 150 feet of chain is a good idea, but if every other boat in the anchorage is riding on 75 feet of chain or rope, you create a hazard when the wind or current shifts, because your boat will swing in a much larger arc than the rest.

The "Cowboy"

We saw a person on a small boat do this once: The boater took his little Danforth-style anchor by the chain, and whirled it around like a lasso. Then threw it in the general direction where he wanted the anchor. He immediately took up all the slack (no time for the anchor to dig in) and tied the rode to the bow cleat.

The Right Way

Select the Center of Your Anchor Circle

Carefully review the anchorage, and have an understanding of the wind and current changes that will take place while you are anchored. Boats with shallow keels and high windage (like powerboats) tend to align with the wind, whereas boats with deep keels and low windage tend to align with the current. Pay close attention to your neighbors and any underwater obstructions that may be within your swing circle.

When in Rome

Study the anchoring techniques of the boats that are near your selected spot. Are they using one anchor or two? Are some boats on moorings? Ideally, you want your boat to swing in a similar manner to the other boats in the anchorage. Do what they do, and you should be fine. Boaters with local experience are a great resource to learn the best way to keep your yacht secure at anchor.

Lay Your Rode Carefully

Don't be a "Dumper!" Approach your anchoring spot slowly, and stop the boat with the bow over where you intend to set your anchor. Lower your anchor until it just touches bottom, then allow the boat to slowly drift back while laying chain and rode. Pay out the rode at the same pace as the drift. Don't let one get ahead of the other! Your rode should drop almost straight down from the bow as you lay it out.

Use Proper Scope

Scope is the term used to refer to the ratio of the length of chain and rode to the distance from the bow roller to the bottom. For example, if the water is 10 feet deep, and your bow roller is 5 feet above the water, you will need to pay out 105 feet of chain and rode to achieve a 7:1 scope [(10 + 5) x 7 = 105 feet]. The amount of scope you need depends on the wind and current conditions, they type of bottom, and your ground tackle. Rope and chain rode requires more scope than all chain rode.

Set Your Anchor

Lay out some extra rode for setting your anchor. If you plan to ride your anchor at 5:1, lay out 6:1 or 7:1 for setting the anchor. Setting the anchor allows the flukes of your anchor dig in to the bottom. Sailboats can do this more quickly than powerboats, because sailboats can "back down" on the anchor. Powerboats must wait it out.

Sailboats:

On a sailboat, once the boat's drift has taken up the slack in the rode, gently put your engine in reverse at idle. Line up a "range" using a two fixed points off to port or starboard, one further away than the other - a piling and a rock, a tree and a spot on the beach, a parked car and a building, etc. Watch your range points closely while the engine is in reverse. When they no longer appear to be getting closer to, or further from, one another, you have stopped moving. Your anchor is now set.

Powerboats:

Since powerboats tend to create a lot of thrust in reverse, they must be patient and wait while wind and waves set the anchor. In calm conditions this can take more than an hour. It is best to set a waypoint on your chartplotter and watch for drift from this point.

After your anchor is set, haul in the rode until you are at the proper scope.

Secure Your Rode to a Bow Cleat

Your windlass is not designed to take the load of your boat riding on anchor. It is just designed to raise and lower it. Your anchor rode should be securely fixed to a cleat at your bow.

Tricks for All Chain Rode

Use a Snubber or Bridle

All chain rode is noisy when tied off on deck. As the boat gently swings at anchor due to wind and waves, the chain clatters as it shifts around in the bow roller. No big deal when you are having lunch, but this becomes quite annoying for someone trying to sleep in the v-berth!

A snubber is a short length (usually 10 to 15 feet) of nylon rope appropriately sized for anchor rode. At one end, a chain hook is spliced on. There are many types of chain hook available designed for this purpose. A bridle is similar, but involves a longer nylon rope with the chain hook in the middle.

Secure the hook to your anchor chain and the bitter end of the snubber or bridle to the bow cleat. Let out more chain until the snubber or bridle takes the load. Now sleep better!

Cut Down on Swinging

Some boats just seem to swing like crazy while anchored. Subtle changes in wind cause high windage boats to swing significantly, especially if the boat has a shallow keel. A trick we learned while cruising on our sailing catamaran was to lay out a lot more chain once the bridle was in place. When the boat is fairly settled in place, let out enough chain to make a pile on the bottom, right below the bow roller. You will be amazed how much this keeps the boat from swinging!


Conclusion

Your anchor and ground tackle are like the brakes on your car. They are the most important safety equipment! Whether you are just lazing about in a peaceful cove, or holding your yacht off a lee shore, proper anchoring technique is essential to safe boating. Your crew and guests, and your insurance company, will thank you.

Happy cruising,
Tim

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