In China, the standard length of each marine anchor chain is 27.5m, and in practice, there is also a section of 25m. The country using the imperial system is 15th (Fathom), and the metric system is 27.5m. A complete marine anchor chain include: chain outboard shot, chain end shot and mid chain. Except for marine anchor cahin with SP, the number of links in each chain should be odd to ensure that the connecting links or connecting shackles can lie flat in the sprocket seat when passing through the windlass. successfully passed.