I have a 2005 Sundancer 340. My...

[Pooh]

I have a 2005 Sundancer 340. My raw water intake has been fouling nearly every time out. Have to clean strainers constantly. It is a very heavy seaweed year in Puget Sound particularly in my Marina.

any suggestions on how to reduce problem?

[wingless]

Mount oar locks and get a set of looong oars...

On my boat I removed the factory scoop hull inlet / strainer part and replaced it w/ a plain mushroom part. The mushroom was covered w/ this Groco APHS strainer. It was of-course electrically bonded to the bonding system by using one mounting point as a through bolt, instead of a screw.

https://www.groco.net/products/raw-water-strainers/hull-strainer/aphs-series

Another plus is that those factory scoop parts are impossible to clean marine growth from the interior. The Groco part has a drop open door, permitting unfettered access to cleaning both the through hull and the back of the screen.

The Groco APHS won't permit seaweed to reach the strainer.

[Grizz]

On the Great South Bay, Long Island we use EEL grass strainer. If EEL grass can't get through the seaweed in Puget Sound shouldn't be a problem.

[wingless]

Is there a link to the recommended EEL grass strainer part?

The OP concern is not getting through the strainer, but filling the strainer, requiring frequent emptying. How does a different strainer address the OP's issue?

[Grizz]

Take a look at these strainers:
http://www.marineengineparts.com/cooling/intake-strainers-inboard/south-bay-strainers.html

[Grizz]

If it doesn't get into the boat it can't clog your internal strainers

[wingless]

Thanks for the link.

Yes, those Buck Algonquin external hull strainers are similar to the Groco APHS strainers that I linked previously, that I installed onto my boat. Both will keep the internal raw water strainer clean of marine growth.

Those Buck Algonquin external strainers will permit cleaning the strainer interior and though hull by sliding out the screen for removal. The Groco permits cleaning the strainer interior and the through hull by hinging the door open.

[Pooh]

Wingless is correct. I can clean the strainers but it is clogging at the thru hull. The ability to unclog the thru hull without a diver or pull the boat out is ideal. I have now started back flushing and that has helped. Planning on changing out to the grocery next the boat is out do water.

[Pooh]

Changing out to the Groco......

[wingless]

My boat now has a custom designed exhaust that permits me to fresh water flush, followed by soapy water, followed by Salt Away after each usage, then I drain the exhaust bone dry until the next usage.

Part of my flushing procedure is to dump each of those flush chemicals back through the seacock and the hull strainer. That back flush is also helping me keep my hull strainer and through hull clean.

Don't forget / neglect to make one Groco mounting fastener a through bolt to permit bonding the part. When I did mine, I drilled a larger diameter hole, filled it w/ epoxy thickened w/ filler, allowed it to harden, then drilled the correct size hole to protect the hull from water intrusion, should the sealant fail.

[wingless]

The factory installed these Groco STH scoop strainers w/ slot opening on my boat. I hated these strainers. The interior was impossible to clean, even on the hard. It permitted interior contamination, like experienced by the OP.

https://www.groco.net/products/fittings/scoop-thru-hull-fittings/sth-series-scoop

My experience w/ the Groco APHS hull strainer has been positive and I do not hesitate to recommend these parts.

When I selected / installed mine I chose THE LARGEST parts that would fit on the hull, to maximize cooling flow rate. There was analysis required to determine where / how to best effect the bonding. All worked out fine.

https://www.groco.net/products/raw-water-strainers/hull-strainer/aphs-series

[Merlin]

I'm just north of you and had to use the taps (that I installed to help prime the raw water pumps after the boat has been out of the water) to back flush the exterior strainer, saved the day for me. They also let me fresh water flush thing out with the boat in the chuck.

[Merlin]

I have an 06 340 had to replace the raw water psi sensor on the port side this year. I was getting a low cooling water alarm on and off. Was told that they start to fail after 10 plus years because they are in raw water all the time. Could be part of the problem, there is a page on the Smart craft that shows the psi. Swapping the sensors with the other engine is very easy and will confirm if that's the problem.

[Pooh]

Thanks, did have to change out sensor, of course did both..

[Pooh]

Thanks all for input. Had boat hauled out and had yard use a dremel tool to open up the thru hull so it is less likely to clog and if I pick up junk it will be caught by strainer which I can clean out unlike the bottom....Wingless will be looking at your system in the off season.