What is this? It is the first thing after the seacock for the raw water line.
(http://i1151.photobucket.com/albums/o638/SailorRalph/Boatpart_zpsf6dd09da.jpg) (http://s1151.photobucket.com/user/SailorRalph/media/Boatpart_zpsf6dd09da.jpg.html)
The next component is the transmission.
Ralph that is the sea strainer, the bottom has a stainless steel catch basket in it to be removed and cleaned. hope that is some help. Allen
Yes - that helps. I didn't know it needed any kind of maintenance.