Sounds easy enough, right? Just push until you are clear of the dock and off you go. But, if your boat is rather large, and there is a lot of wind or adverse current, it is not that easy.

If the wind or current is moving parallel to the dock, this is a pretty easy scenario. Then you simply need to use a spring line and good fendering. The spring line should be used on the opposite end of the oncoming current or wind. For example, if your bow is into the wind/current, then you would put a spring line from your aft cleat and go forward on the dock. Just release the bow line and hit reverse a bit and the bow will swing out. Once clear, motor forward and retrieve your aft spring line.

(Note, if there is no one on the dock to undue your mooring line, here is a good tip. Have a dock line that has a clean end – no knots, kinks or unravelings. Then for your spring secure the line to your cleat, around a piling or cleat on the dock and back to the original cleat. Once you have sprung the boat off the dock, untie the clean end and let it go. Then retrieve the line. The clean end will slide around the dock cleat and back to the boat)

If the wind is perpendicular to the dock and blowing on to the dock, this is a much more difficult situation. You best bet is to spring your bow line. Use hard rudder in the direction that will kick your stern out and away from the dock. Once the stern is out far enough to clear, reverse rudder and engines and retrieve your bow spring line.

Source: americanboating.org