There are eight knots that are taught during the RYA Competent Crew course. These knots are the bowline, clove hitch, round turn and two half hitches, the reef knot, rolling hitch, figure of eight, the sheet bend and the double sheet bend.
Don’t panic, you won’t fail if you don’t know them all and the more practice you can get, the better! Once you’ve got the hang of them, you will find you’ll stop using the granny knot (you know - the one that everyone does) and you’ll be using the correct knots all round your house and garden, perhaps even tying the dog’s lead!
Here are the basic knots for any competent sailor:
The bowline is used for making a fixed loop at the end of a line. It is used for tying sheets (ropes) to the clews of sails and also used for mooring lines.
The clove hitch is typically used for tying fenders to the guard wire.
Round Turn and Two Half Hitches
The round turn and two half hitch is used for tying mooring lines to rings, on a pile for example, you would also use it for tying a dinghy ashore. The great advantage of this knot is it can be released under tension, unlike a bowline.
The reef knot is used for tying the ends of two lines of the same diameter together. It can be used for tying up the foot of the sail when reefs have been put in, hence its name or for extending a length of rope. You should not use this for tying two different size lines together.
The rolling hitch is used to grip onto another line. One of its best uses is for relieving tension in sheet lines that have a riding turn on the winch. It could also be used to get an object out of the water ie a spar or mast.
Figure of Eight
The figure of eight is used as a stopper knot on the end of a line. Used for example on halyards, so that the line does not disappear up inside the mast by accident. It can also be used as a temporary measure to prevent a rope fraying.
The sheet bend and double sheet bends are used for joining two lines (ropes) of unequal diameter to make a longer one. Very handy when you are trying to get a shore line across a wide raft of boats. A double sheet bend is no stronger but it is more secure than a single sheet bend.
To understand how to tie these knots, and many more, consider buying a book on knots published by the RYA. Alternatively, YouTube is great for learning your knots, but make sure it is a credible source!