Had kind of a scary incident on Saturday on the Mississippi. While we were heading back to the launch a heavy downpour hit us. We decided to stop at a public city dock and get something to eat while we waited for the rain to stop. The dock is your basic floating straight line with room for maybe 8 boats. We landed between a wakeboard boat in front of us (upstream) and a larger cuddy behind us. One of my passengers tied the bow line over the top of the wakeboards line on the shared cleat and I tied the stern line the same on the cuddy's cleat. I inspected the bow tie and it was wrong so I untied and showed my friend how to tie it correctly. Point being I knew it was tied correctly. We went to eat and I visually checked on the boat a couple times from the restaurants deck. Everything seemed fine but the downpour continued. When the rain finally stopped all the other boats were gone except mine and it was sticking out 90 degrees because the bow line was not attached to the dock. The current had the stern line under a lot of pressure as the boat was sideways in the current. So either the wake boarding boat did a bad job of retying my bow line or didn't retie it at all. What is the etiquette for sharing the same cleat?