Anchoring
by Captain Tom Martin
GOAL: Anchoring any vessel in most conditions.
READING REFERENCE: Anchor types and their purpose.
Whether you're anchoring for lunch, a swim, fishing or overnight the process should remain the same. Variables are "bottom type," "current," "wind," "water depth," your "gear" and the proximity of other vessels.
Preparation and Communication are the Keys
All anchoring gear should be tested and set up in the ready state before you leave the dock. Many people put their anchor gear away after use in the ready mode.
Communicate to each crew member involved and often to those that must stay out of the way, what you intend to do "step by step." Everyone who has a task must know how to do what you ask of them and when to do it.
The standard length of rode to depth is six or seven to one in good holding ground and 7 to 11 in bad or windy conditions. An easy way to measure is marking the chain and line (rode) before hand every six or seven feet. If you haven't measured ahead of time, use your arms length to measure off line. On average men have a six feet arm span women around five feet. I like to use the old mariners fathom per foot rule since a fathom is six feet. Anchor rode is the combination of rope and chain you're using.
A crew member should tie off the anchor rode at the length you have chosen (you can always adjust it later if necessary). When instructed by you they lower the anchor steadily until it runs out. You can have them announce each fathom as it goes out.
The boat rotates on the anchor in a circle that is the radius of your circle. The longer the scope (length of anchor rode used) the better the boat will stay in place.
Combining chain and line of appropriate strength and length improves the ability of the anchor to hold. Chain being heavier keeps the anchor pointed downward and holds better.
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How to Anchor
You have chosen a spot off a sandy beach for an afternoon swim. The chart says it is a sandy bottom and about six feet of water. A plow (variation) or danforth type is suitable for sandy bottoms. Your depth sounder confirms six foot of water when you arrive at the spot.
Observations to make on wind and current, plus proximity of other anchored boats! Is there too much wind or current to allow you to anchor safely? You can compensate some for both excess wind and current by increasing scope on the anchor rode but if they switch direction you run the danger of the anchor dragging. Note the place where you drop anchor often is not exactly the spot where it sets. Note also that spot is the center of a circle which the radius is the length of rode considering the depth.
Maintain your position over the spot chosen as your crew lowers the anchor, after 12 feet of the necessary 36 feet of anchor rode engaged engine in reverse for several seconds. Try not to gain too much momentum as they finish lowering the anchor.
The weight of the vessel should set the anchor. You should feel it set as the boat's backward motion will abruptly stop. If you feel that the abrupt stop was stiff enough then you are anchored. If you choose to reassure yourself it is well set engage the engine in reverse until you see you're moving, place it in neutral and wait and see if you stop abruptly again.
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