Hi Sid,
Ralphy sent me a PM which I replied to explaining what they are, I was in a bit of a hurry earlier (I actually managed to go ashore in Sharm el Sheikh) so didn't want to retype my reply at the time and hope that Ralphy would come along and cut and paste from his PM's.
They are generally known as morring platforms.
On older ships the fo'c'sle was almost always open, recently we have figured out that keeping critical equipment on the most exposed part of the ship is probably not a good idea, cargo ship owners have discovered that machinery is better protected on covered fo'c'sles and the big cruise companies who no longer want their ships to look like ships have discovered that covering the fo'c'sle makes their ships look even more like accomodation barges which seems to be their ultimate goal in life.
They are lowered during arrival and departure and, as you say, allow the officer in charge of the mooring station to see what is happening on the quay side, they also allow him / her to see the lead of the anchor when dropping or weighing.
They are then closed for the passage making the mooring deck weather tight.
