One of the most used and popular knots in the boating world is called the bowline. This knot creates a loop that will grow tighter depending on the amount of pressure that is on it. It is an easy knot to tie and also untie and has been used for over 400 years for sailing and other vessels. When the coast guard goes out on a mission to save a stranded boater, they tie a bowline knot to help assist them hoist the stranded boaters from the sea. This is just one of the versatile knots displayed on this guide from SeattleYachts.com that shows 16 of the most important knots for sailors.
The figure eight knot visualized on this graphic is also a good one to know. Tying a figure eight knot into a rope will create a stop on one end, helpful for when you are placing fenders on the side of your boat or when you want to make sure your anchor is secure. Learning to tie knots has never been easier with these step-by-step photo guides.