“Better to know a knot and not need it, than need a knot and not know it.”
A Round Turn and Two (or more) Half Hitches is useful for attaching a mooring line to a dock post or ring.
The Bowline makes a reasonably secure loop in the end of a piece of rope. It has many uses, e.g., to fasten a mooring line to a ring or a post. Under load, it does not slip or bind. With no load it can be untied easily. Two bowlines can be linked together to join two ropes. Its principal shortcoming is that it cannot be tied, or untied, when there is a load on the standing end. It should therefore be avoided when, for example, a mooring line may have to be released under load.
Primarily used in sailing when attaching fenders to the side of the boat. It should be distrusted as a holding knot as it easily slips and comes undone when not under load.
The Cleat Hitch secures a rope to a cleat. It is deceptively simple and an unwary skipper who invites visitors to cleat a mooring line may be astonished and dismayed by the unsatisfactory results