Even in an age of joystick docking, with pods and bow and stern thrusters on many new boats, you still may find yourself needing to use spring lines to get off a dock. First off, your boat may not have all those useful devices, and second, they may not always work. In any event, you’ll be a much more confident skipper if you – and your crew – know how to use springs, particularly if you’re in a tight situation or facing adverse wind or current.
Here’s a great story, with diagrams and video, about how to leave a berth using spring lines from Motor Boat & Yachting, the British magazine. The instructions are very clear, and they work. I know; I’ve used these techniques many times on my single-screw Grand Banks 36, which did not have a thruster of any kind.
My only caveat here is to be very aware of your swim platform in the situation where you’re using a spring line aft to force the bow off the dock. Even with an extra fender or two, you still could put your swim platform in peril here, depending on its size. I personally found going forward against a bow spring, forcing the stern out, easier and safer, but that’s just me. And you’ll definitely want to keep a very gentle touch on your throttle(s), whether you’re going forward or aft; this is not a time to go banging around. Take a look:
https://www.mby.com/video/leave-berth-using-springs-104351
