Fish Blocking Raw Water Intake

[davidkahn53]

Sharing an unanticipated sailing adventure, or perhaps they are all like that. I was moving my Pearson 33 on Chesapeake Bay this weekend and arrived early to get organized. Since it was a cold morning, I started the engine to warm up, of course checking the exhaust for cooling water. As I was about to leave, fortunately checked the exhaust again and saw no water coming out. There was a bit of seaweed in the raw water strainer but nothing that would create a blockage. But I could feel what felt like a complete blockage by something rubbery where the raw water came into the strainer. To make a long story short, after multiple efforts to clear the obstruction without success, had to take apart the hose and strainer to figure out what it was. It was a small fish that had been sucked into the water intake and lodged just in front of the strainer where it was totally blocking the intake. After removing the fish, everything back to normal and an uneventful trip, albeit several hours later than planned.
Lessons learned: 1. Checking the exhaust regularly paid off; if I hadn't noticed until after leaving the dock it would have been a much bigger problem as I was single-handing and would have had to get a tow. 2. Allowing lots of extra time allowed for 2 hours of fish extraction and still plenty of time to get to the destination. 3. Just when you think you have everything covered and thought through, a fish swims in your engine intake.

 

[NotCook]

Well, I certainly haven't heard that fish story before!

I'm assuming the fish did not survive the encounter...

 

[Benny17441]

What adventure? Fish Taco Night!!!

 

[Scott T-Bird]

It sounds like a simple task to separate the hose from the strainer, but in a confined space, it can be a nightmare to try to remove some parts. I had that same problem with eel grass last summer, except the clog was at a 90 degree fitting at the thru hull. After a lot of effort to remove the hose from the fitting, I still couldn't clear the clog until I dove under the boat multiple times and prodded with just the right pointy implement. That reminds me that I need to remove that fitting and replace it with an in-line fitting.

 

[NotCook]

After a lot of effort to remove the hose from the fitting,

Just curious, Scott, how did you keep water from coming into the boat at that point? Was there a seacock involved, and where was it in relationship to the fitting that you could access from under the boat? Our boat is one that is not easily hauled - only so many places can do it - so much of our maintenance is done while in the water, as in the case you just described. That's where a plunger like device, or at least a heavy waterproof material over the outside comes in handy.

You are right about hard to get at places. Heck, seems like every time I have to take off a fuel line connection I have to cut it off and make the line another half inch shorter - those hose barbs really do their job of holding onto the hose!

 

[Gunni]

Yep, likely a herring (menhaden). I had one lodge in my A/C raw water intake last year. When I pulled he hose off the thru hull it shook out. It had been in here awhile because the fins were cropped and stunted. Keep an eye on your discharge water.

 

[WayneH]

Not all fish make it into the hose. I was getting ready to clean a hull and I always take pictures of the hull beforehand so that the owners know how well their paint is holding up. I told the owner of this boat to cancel her A/C service call.

Yep, he's stuck up in there.

 

[capta]

Most quality boat manufacturers use seawater intake strainers, or thruhulls with intake strainers. The only place we get the lil fishies is the head intake, because both the engine and generator have seacocks with strainers. Something to think about on your next haulout.

 

[Ron20324]

[QUOTE="NotCook, ...Well, I certainly haven't heard that fish story before!...QUOTE]

I recall someone had a fish in his head pump???

 

[Terry Cox]

Our engine through hull fitting has a screen on it, but the head intake does not. A few years ago, after sitting idle for some time, I used the aft head to bring in sea water to flush, but nothing would come in but a little black water with pieces of some rotted stinking creature. In order to clear the clog I used a fitting to connect a municipal water hose to the intake line. Blew it right out, whatever it was; likely a dead fish.

 

[Ken Cross]

I once had seaweed with jellyfish up against it just against the strainer. Not too easy to get it out of the tubing.

Ken

 

[Apex]

hmmm, sounds a little "fishy" to me......

 

[Daveinet]

It would be nice if there way a way to reverse the flow, and blow out what ever is caught in there. Maybe a t-fitting and a hand pump.

 

[Gunni]

If it is a small clog close to the intake you can pull the hose above he waterline and use a dinghy foot pump or scuba accessory hose to back flow the hose with a blast of air. My little herring was too far up for that fix.

 

[Scott T-Bird]

Just curious, Scott, how did you keep water from coming into the boat at that point? Was there a seacock involved, and where was it in relationship to the fitting that you could access from under the boat?

My thru-hull has a seacock and then a 90 degree fitting above the seacock with the barbed end for the hose. I tried to use a wire (about 6 or 8 AWG, I think) that might navigate the bend, yet be stiff enough to unplug the eel grass. That didn't work. So then I prodded from underneath with a long slender awl. That helped to push eel grass into the seacock but obviously not past the bend. By working the seacock, I could chop up the eel grass a little at a time. At first, I would get just a trickle of water. I could also get a some bits of eel grass when opening and closing. So I continued by prodding some eel grass, then climbing back on board to work the seacock, getting a few more bits each time and the water flow also seemed to improve. After several cycles, a clot of eel grass finally came out and all was clear.
I've thought about keeping a bicycle pump on board for just such a reason, but have not followed thru on that notion! I also think that a strainer over the hull opening would be a good idea at this point. My seawater strainer also became filled with eel grass on more than one occasion this summer, so it's a condition that isn't going away, I can see. I also can't believe the smell of that stuff when I clean out the strainer!

 

[davidkahn53]

Well, looks like others have had a similar fishy experience. As I was taking apart the strainer, I was thinking that a plumber's snake small enough to go through the hose would be a good thing to bring along if ever going offshore.

 

[Scott B]

Yep, been there.......

 

[gettinthere]

Aft head intake clogged. closed the seacock and pulled the pump apart. found a foot long snake in there! and it was tail to the pump. either the suction of the pump sucked it in tail first or it managed to get turned around before drowning.

I HATE SNAKES!

 

[Scott B]

Aft head intake clogged. closed the seacock and pulled the pump apart. found a foot long snake in there! and it was tail to the pump. either the suction of the pump sucked it in tail first or it managed to get turned around before drowning.

I HATE SNAKES!

You've got bigger snakes to worry about tonight........ . ( oops did I mention politics? Don't tell the mods or this will get bounced to the War room. . ).

 

[Scott T-Bird]

Well, the "deplorables" did have their say!