Sorry for the recent lack of photos but family and work have consumed all of my time.
Here is an image of the sea chest in the engine room. The other DDs I have seen have the "shorter" sea chest not the tall one shown here. The taller sea chest extends above the water line so one could open the sea chest to clear a problem with out flooding the engine room.
This is yet another photo where the dumb photographer did not take enough images.
On the other DD's the shorter sea chest has multiple valves for the various salt water feeds into the boat. I think these valves are hidden in this photo by the taller sea chest.