Anchoring in very shallow water.
When anchoring, the usually accepted minimum scope of chain or rope are, 4 times and 6 times the maximum depth of water respectively.
The intention of laying out so much chain is to ensure that the pull on the anchor is as horizontal as possible.
When you anchor in very shallow water the height of the bow above the water should be taken in to account. If the water is only 3m deep and the bow is 1.5m above the sea, this extra height is a large proportion of the total.
In this situation the depth should be assumed to be 4.5m for the purpose of calculating the amount of chain to lay out.
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