My engine swallowed a fish and got indigestion

[allen]

As some of you know, I have a Lapworth 36 with a Gray Marine engine that is raw water cooled. Friday I want to the boat to check everything out before my sail today with my daughter. Engine started but no water out the exhaust. I back flushed the exhaust manifold and out came a 3 inch long fish that looked like it probably went through the water pump. Without the fish, the engine worked as it should. Somehow I sucked a fish in the through hull. The boat is 64 years old and for all but 20 of those years there was just the through hull, a hose, and the pump. For 20 years I had a bronze strainer over the inlet but removed it 5 or 10 years ago because I was a fanatic racer and didn't want the drag. Besides, I was told the strainer was to prevent sea grass from getting in the engine and we just don't have any of that in San Francisco Bay where I sail. We just have mud.

I guess this is either a sufficiently rare event that I should not worry about it or else it is bad practice to have an exposed raw water inlet and I should do something. I see water filters but I am not sure if they are for fish tanks or engines. I could put a strainer back on. Or perhaps I just need to look over the side and see if there is a school of fish hanging out before starting the engine.

Anyone have some best practices to share?

[rcvesselstyn]

I believe that to be pretty unique. Over the years we've clogged our Inlet with kelp about three times. Once so bad I had to pull the hose off the through hull and pull out a kelp strand from the hose. All our inboard sailboats have just had the through hull hole. So that's almost 40 years and only two problems. We also had a powerboat to dive from in the mid-70s that had a strainer on it intake. Even it got clogged with kelp once. Down in Long Beach after the rains there are a lot of plastic bags in the water. Washed down from the river. It doesn't seem to matter whether you have a strainer or not if you're going slow you can get clogged. I think you just got lucky.

[allen]

Thanks for the reply. That is reassuring.

I don't know if anyone else cares to chime in as to if they have input screens or not but if so, I would appreciate it.

Allen

[Capn ken]

Good morning, I have a 1972 cal 29, and I have a in-line strainer for my atomic four. Probably not necessary but I like to look at the hardware.

[Sailmiles]

Hello!
Belt and suspenders kind of guy, I have an external and in line filter as well. No issues on our 40 year old 34III, Westerbeke 30.

Capn Bob

[allen]

I happened to see my diver today and told him what happened. He said those fish like to hang out in through hulls. He finds them in there often. He sticks his finger in and feels them and then they swim out. He said they were the leading cause of clogged engine and heads and such. They are not in schools so looking over the side for fish isn't going to work. He took a photo when he was surveying a leak I am fighting.

[Mary Mac]

Interesting! Thanks for sharing.

[SailingChris]

Sounds like a strainer is in order, even if it creates a tiny drag. Make up for it by keeping the bottom paint smooth. But for those of us in zebra mussel/quagga mussel territory (the Great Lakes, e.g.), strainers create their own problems. Last summer the outboard that powers my other boat in & out of the marina stopped peeing water and started emitting steam. Not good. I figured the impeller had died; extracted the OB from its well and took it home. On a whim I took the water intake strainer off. Behind it and in the uptake tube there were mussell shells. I pulled 'em out with a wire, started the OB, and it peed cooling water again. I'll check it annually now. Before, my theory was that heated water would probably drain back and cook any incipient mussell growth. So much for that theory....

Chris Campbell

[rcvesselstyn]

As I said earlier I don't have a strainer on my raw water inlet . I do have a bronze Perko water filter connected to my raw water line. I rebuilt it and cleaned it when we bought the boat. I haven't had to clean it since. That was a7 years ago. I would think a filter like this would take out any blennies that might take up habitation in your through hull.

[allen]

I asked my shipwright to put the strainer-scoop back on the boat during my latest haul out. He forgot. So now I am going to add an inline strainer in the engine compartment. I am having trouble deciding. I have been reading reviews. This one clogs. That one has screens that rot away in salt water. I need a strainer that will keep a fish out, not a micro-organism.

EDIT: Well, I bought a Geoco ARG-755-P. Hope it was a good choice. It has the plastic basket with pretty large holes so should be a good match to my engine. Thanks to everyone who offered advice. Now if the Epoxy holds on my manifold I may actually be able to go sailing this year.