For this scenario picture trying to get your boat into a mooring (parking) place that has just about enough room for your boat. Unlike what you learned in auto driving school for parallel parking, you do NOT pull alongside the forward boat and back in. Remember the Seinfeld episode where George was backing in and another chap was pulling in? They had a standoff for the whole show…blocking traffic, etc.
Well, in docking a boat, George loses.

Assuming you are landing port side to the dock, pull the bow in and use a spring line from forward on the boat to a cleat or piling aft of that point. Then the helm should be put hard right and given power. That will swing the stern into the dock. That is the art of springing your boat into the dock because you are using a spring line.

To spring off the dock, use the same spring line from the forward on the boat (bow) to a cleat or piling aft. Now turn the helm hard left and apply power. Once the stern kicks out, release the spring line and back out.

(Note on the spring line: Assuming there is no one on the dock to help, use a “clean” spring line. That means there can be no knots, loops or anything that will catch on a cleat, dock or whatever. The spring line goes from the boat, around the cleat and back to the boat. Once the boat is sprung off the dock, release the bitter end and pull the clean line through the block and back to the boat.) You are then clear to move about the country.

This helpful boating pointer is provided by Catamaran Sailors Magazine,http://www.catsailor.com/.These tips are useful to boaters of all types. ABA assumes no responsibility or liability for events that occur due to actions you or others on your behalf take based on the information given. You are proceeding at your own risk.

Source: americanboating.org