The anchor chain's function

2. The weight of the anchor chain is negligible for the ship, and the friction will not play much role. Generally speaking, when anchoring the ship, the anchor chain is straight, which can basically ignore the effect of friction. If you are on the beach, you will find a lot of small fishing boats whose anchor chains are thick ropes.

3. From above, the anchor chain is straight, but there is a section under the water that is nearly parallel to the seabed (actually close to the seabed). The anchor provides the grasping force, which is then transmitted to the ship through the anchor chain, so as to resist the influence of the external load of current and wind waves on the positioning. The reason why there is a section close to the seabed is to consider the influence of the force. Think about it. An anchor is easy to anchor when the anchor chain is pulled straight. There is a section close to the seabed, which can provide a margin, which is possible within a certain range.（the anchor chain)