Not the answer I'm looking for, I'm afraid. There may also be klaxons
However, your 'VERY FIRMLY' intrigues me. Care to elaborate?
Picture 1 shows the initial state.
Picture 2 shows the boat so firmly anchored so that it does not rise with the tide, and so the (weighted) rope ladder starts to be submerged
Picture 3 shows the boat (and rope ladder) rising with the tide and so the ladder does not get submerged at all (perhaps that was the droid you were looking for?)