How long should the anchor chain be to ensure safety at anchor?

The golden rule for safe anchoring: use a length of chain equal to 3 to 4 times the water depth, and up to 5 times if conditions deteriorate (gusts, swell, uncertain seabed). For example: if you’re anchoring in 5 meters of water, you should let out at least 15 to 20 meters of chain.

Good to know: this length is measured from the water’s surface to the bow (the anchor point on the boat).

Never forget that your anchor is your primary safety measure: how well it holds depends as much on the length of the chain as on the nature of the seabed and how you’ve set it.