What is the purpose of a boat anchor

The main purpose of the anchor is to hold and stabilise the boat. From the following aspects. 

1, the most basic condition for an anchor to work is to hook something at the bottom of the sea and so on.

If the anchor chain is not long enough, the anchor will not work. If the seabed is flat, or the anchor hooked things are not fixed, or hooked not too firmly, if the wind and waves are calm, but the waves are too large, resulting in the anchor can not hook things, will make the anchor lose its role, which is called "go anchor", the ship at anchor during the time of the anchor, go anchor, is very dangerous.

2、The weight of the anchor chain is negligible for the boat, it will not play a big role.

Generally speaking, when the boat at anchor, the anchor chain is straight, do you think there will be any friction on the anchor chain at this time? If you are on the beach, you will find a lot of small fishing boats with anchor chains that are thick ropes.

3, in the boat above, the anchor chain is straight, but underwater there is a section of the seabed and the seabed is close to parallel, in fact, the anchor is attached to the seabed to provide grip, and then through the anchor chain to the ship, thereby resisting the currents, wind and waves of the external load on the positioning of the impact. The reason why there is a section against the seabed is to take into account the effect of forces, and having a section against the seabed can provide a margin, within a certain range is possible.

The weight of the anchor is not great, but there are rules about how big an anchor is for how big a boat, and this is due to the fact that the anchor can generate a grip as well as its own inertia, and the anchor chain friction also plays a role.