There are five basic knots that every boater should know. All knots used by boaters are designed to be easy to tie, take a tremendous amount of strain and then be easy to untie.
The five knots are as follows, and you should practice until you can tie them without thinking about it.
In order to secure the boat to a dock or secure a line to the boat, you will probably use the cleat hitch. Take the line to the ear of the cleat furthest from where the line comes from (the load). Take one wrap around the base of the cleat and then start a figure eight across the top of the opposite ear. Finish with a half hitch turned under so that the line is coming away from the cleat in the opposite direction from which it came in.
Also called the "king" of knots, the bowline is very versatile. It is used to form a temporary loop in a line that can then be put over a piling or cleat. It can also be used to attach a line to an eye. This knot won’t slip or jam. Start by making an overhand loop which looks like a six (see first figure). With the end of the line, come up through the hole in the six, around the back of the line you’re holding and back down through the hole in the six. Grab the part of the line that went up through the hole and the part of the line that came back down through the hole in one hand, and also the top of the line you were holding in the other, and pull.
Simple to make, the square knot is used for lots of light duty, including tying things down. Start with an overhand knot like you were beginning to tie your shoe. Keeping the ends of the lines in your hand on the same side, cross them again and tie another overhand knot. If you don’t keep them on the same side you’ll end up with a granny knot, which will jam.
Used to permanently tie to a piling, mooring or ring. Simply take a full turn around the object being tied to and take two half hitches around the line itself. Over and up through and under and down through.
Used to temporarily tie to a piling, this knot can come loose. You may add a couple of half hitches as above to make it more permanent. This knot is simply two loops with an end tucked under.