The length of anchor line is called "Scope" by mariners. The scope of your anchor line should be 5 to 7 times the depth of water that you're anchored in. It should never be less than 3 times the depth. In other words if you usually anchor where the water is 20 feet deep you should have a MINIMUM of 100 feet of line.
The anchor line should typically be at least 7 to 10 times the depth of the water where the anchor is deployed. This ratio ensures that the anchor has enough scope to hold effectively, allowing for better holding power and reducing the risk of dragging. For example, in 10 feet of water, your anchor line should be between 70 and 100 feet long. Always consider factors like wind and current when determining the final length.
When anchoring your boat in 20 feet of water, a common rule of thumb is to use a scope ratio of 7:1 for calm conditions. This means you should let out 140 feet of anchor line. However, if conditions are rough or if the seabed is particularly challenging, a scope of 10:1 may be more appropriate, requiring 200 feet of anchor line. Always consider factors like wind and current when determining the length of your anchor line.
The inboard end of the anchor line can be fastened to any secure point on the vessel.
the length should be 8 times the depth of the deepest water you are planning to anchor in.
bow
stern
A bow cleat
the bow cleat
stern
An anchor line is a very heavy rope or chain by which a ship's anchor is hoisted.
The new New Zealand Anchor advert is by Bobby Darin, called Long Line Rider.
the length should be 4 times the depth of water in which you are trying to anchor.