Can't comment on the first while in a dock, but I have experienced this at anchor from vessels far away. Water transmits sounds is strange ways.
For the second, many masts have electric wires in them which may not be attached to the inside. So any movement of the vessel will cause those wires to strike the inside of the mast. You clearly won't hear that underway given other background noise. But when docked, noise such as this will become noticable.
Last edited by arja; 01-16-2009 at 03:56 PM.
Reason: correct comments