Threefer.

A ship coming in from The Wash this evening. The small portakabin is the coastguard station and the lighthouse is the west one, the east one was the home of Sir Peter Scott at one time but is currently undergoing repairs and is covered with scaffolding and fabric.

And yes it is coming in from the sea - the turning berth at the port gets silted up so it can be hazardous to use and if the ship gets stuck across the river it can break its back, so that is why some ships reverse into the port..