Ill be adding an anchor wash down when i get back to the
boat so been giving it lots of thought.. I'm not a big fan of below the waterline thru-hull fittings .. as of now we only have 2.. one for
raw water cooling and a second one next to it for future AC
cooling line..
My thought/hope is that my wash down pumps inlet will be a hose that I toss over the side from the bow when I need to use it.. Pump will be installed below
deck..
Just a thought..
As for installing the pump below the waterline goes.. the pumps I've been looking at seem pretty robust as far as catastrophic failure goes.. but connections to and from them and seacock is another story and obviously potential week link.. Im pretty anal about closing my seacock when not in use.. if you do the same with your seawater wash down inlet then no problem..
The only other concern id have is possible cross contamination if you plan to have fresh and sea water connected via valves... I'd go way out of my way to avoid any possibility of that.. even if it means a whole and separate system..
I'm sure there are some back flow preventers and other ways to avoid cross contamination.. but for my
money.. limited mental capacity and general belief in Murphy's law.. I wouldn't take the chance in contamination of my "survival" water... but like I said.. I can be a bit over the top.