What is this *thing* between my raw water intake and engine

[stantale]

Actually I was just at the boat show and I asked a bunch of experts. No one knew except the venerable Ralph Naranjo (probably wasn't so happy I asked a question entirely off topic from his weather routing seminar ;-)

He surmises it to be a sacrificial zinc, to which all the internal metal surfaces would be tied to via a common bus. So the winner is PorFin who had the same thought.

whatever it is, it's coming off...

[fryewe]

To me, it looks like a y-strainer...cleanable by backing off the hex bolt on the strong back on the cover for the strainer, with a float valve above it, designed to seal off if a high flow rate develops due to a large leak downstream of the sea ****/strainer connection. At the low flow rates that the engine requires, not enough differential pressure would develop to shut off the float valve.

Or maybe none of the above. Would you let us know what you find when you take it out?

Should be easy to check and clean the strainer. Just close the sea **** and back off the hex bolt, roll the cover off and see what's under it. Might have a bit of cork or rubber gasket material to cut a new seal for the strainer cover if the old one tears when you take the cover off.

[fryewe]

..."gasket material ON HAND to cut a new seal"...

[NCboatrx]

The football shaped gizmo is a housing for a replaceable zinc anode. This pencil zinc should be checked at least every 6 months. These are made by Sendure. Here is the link to their catologue, see page 4 of the pdf
http://www.sen-dure.com/Sen-DureCatalog.pdf

[Minnewaska]

Originally Posted by NCboatrx

The football shaped gizmo is a housing for a replaceable zinc anode. This pencil zinc should be checked at least every 6 months. These are made by Sendure. Here is the link to their catologue, see page 4 of the pdf
http://www.sen-dure.com/Sen-DureCatalog.pdf

Game, set, match.

Nicely done.

[Capt Len]

From your picture it looks like two thru hulls side by side .What that about? Jack is right about the anti syphon loop but I think with that kind of filter it has to go on the outlet side.so not much help when opening filter. On Thane I've brought the hose up to a U made of soldered copper fittings. That has a threaded cap that can take a garden hose but I only us it as a vent because I drilled a SMALL hole in it. The down side hose goes directly to the raw water pump. This little gizmo needs to be be checked (poked with a pin) now and then for fluff so should be accessible. This has worked well for me for many years. Any comments? While I'm at it I might as well tell you about the normally open solenoid valve operated by oil pressure switch I put in the side of the aqualift .muffler

[Hudsonian]

I believe the football is an in-line zinc pencil to provide cathodic protection to your cooling system. See page 2: http://www.sen-dure.com/Sen-DureCatalog.pdf