Sad thing is I didn't here this on the dock heard it from a guy that has been fishing with me on and off for a few years and a Maritime grad to boot. Been fishing in NH and pulled into to harbor and told him to make boat fast tight to the dock, when I came back boat was floating about 3' off dock, I asked him why, he told me that there was a big tide here in the harbor and he wanted to make sure that the boat didn't go under when the tide came in. I guess he had not been paying attention to the dock rising and falling with the tide on I piles, for the last week. I don't know if he thought the floating dock went under on the high tide and another dock magically appeared or what. But it might be time for a new mate.