If I'm reading it right Steele and Goodwin both say that there were two riding bitts about 12 feet apart. All the original drawings I have of the Discovery1789 only show one. Mind you my drawings are rather incomplete. Did non navy ships possibly have only one bitts? Even if a ship was built with one do you think the Navy would have upgraded that to two when they purchased a ship? I do have a John McKay drawing that shows two but I think he was working with the same drawings I have so I'm guessing he was using an educated guess?