So yesterday I was running around empty-Kingshead(There's a glitch that you can get into Kingshead without any enemies, people, items, ect. just the fort is left.) with my friend and I saw the secret dock and attempted to jump over to the wall to get to it. I told my friend what I was doing and he disappeared and told me to teleport to him.
There we go, Kingshead secret dock.
Attached below. ^_^