When we were bringing the boat up, we over-nighted at a marina that obviously catered almost exclusively to power boats. (Didn't know that when we made the arrangements. Didn't really matter, anyway.) There were a bunch of boaters hanging out on a dock on the other side of the canal where we were supposed to tie up. First time for us, and I just kind of stood there stupidly, all my knot know-how suddenly completely abandoning me

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One of the on-lookers yelled across "Hang on, I'll be right over." He came over to show me How To Do It. He got the 2nd half of the clove hitches up-side-down and got the 2nd half of the double half-hitches backwards. But it did get us tied up. After my wits returned, and they were gone (didn't want to seem ungracious), I re-tied the knots and added a spring
line (which they also said was unnecessary).
Lesson learned: Probably Not A Good Idea to try to dock in a strange marina, with a new-to-you boat, after a full day's sailing and motoring (through unfamiliar waters), and you haven't had any practical experience with your knots and warp-handling and the like

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Jim