Questions about Carolina Boats/ Sea strainer applications

[Fortunate One]

Am I wrong in assuming most Carolina Boats use a sea chest for raw water distribution?

I've heard that there are a lot of builders using sea chests and not installing independent sea strainers. Is that true?

Are they relying on the screens below the strainers to keep debris out of the raw water system?

Anyone have first hand knowledge?

[darbikrash]

I can't really speak to Carolina boats, but in general, the industry seems to be heading towards eliminating the internal sea strainers that used to be standard on all the high dollar boats, and replacing with external screens.

Case in point is Viking, I believe they are using exclusively external screens. On the higher HP engines, they suck so much water the internal strainers have to be huge to handle the flow, and at some point I guess it gets impractical.

My inboard diesel boats have ALWAYS had internal strainers, but I can tell you where I boat, I've never seen anything of any consequence in the way of debris inside the baskets.

The case for a sea chest is really different than the issue of strainers or screens, the sea chest is designed to reduce the amount of thru hulls in the boat, always a good thing.

[Fortunate One]

We're installing a sea chest for less drag. I've never given the sea strainer issue much thought until now.

Interesting point though about the volume of water required by the big iron. The strainers would have to be so large that yoy coule put your head in one.

I'm curious if this is what the carolina rigs are doing also.

[Graceland]

My 25 has the sea chest and screen with no raw water strainer. The screen is tilted from aft to fwd to aid in keeping it clean as you move through the water. I asked Mac Privette, owner of Carolina Classic, about it. He said he had bogged engines with sargasso in the props but had never experienced a clogging or overheating issue with the sea chest/strainer screen installation he was using.

[Fortunate One]

Originally Posted by Graceland

My 25 has the sea chest and screen with no raw water strainer. The screen is tilted from aft to fwd to aid in keeping it clean as you move through the water. I asked Mac Privette, owner of Carolina Classic, about it. He said he had bogged engines with sargasso in the props but had never experienced a clogging or overheating issue with the sea chest/strainer screen installation he was using.

Now that's interesting, they are doing it on smaller craft also. Since I'll be trolling weed lines I was wondering about the effects of sarrgaso on the sea chest screen. And the owner of Carolina Classic even bogged the engines with sargasso and never over heated the engines. I find that real interesting. I wonder if he has a picture of the screen application.

[JonnyD]

Most builders use a sea chest now. Some do not put the mains in the chest, and most dont use strainers on the mains. On our boat, the mains are in the chest as well as both gen-sets, but the mains dont have a strainer. The gen-sets and all other raw water pumps have strainers. The A/C pumps are not in the chest though. The constant draw of water from them, moving slowly through a sea chest causes much more growth in the sea chest.

[Questsportfishing]

they work great and they were easy to clean we had some big flat screens on the bottom and they had just a small tilt on the bottom. the thru-hull shut offs were inside on the sea chest system worked very well with freezer plate pumps twin 440 yanmar mains a/c washdowns etc. you just have to build them right ...

[Fortunate One]

The constant draw of water from them, moving slowly through a sea chest causes much more growth in the sea chest.

This just gets better and better all the time for a boat junkie like me.

I assume the constant feed of water would provide a continuous flow of nutrients to the critters that thrive in that part of the world. Interesting, I would have never thought about that myself.

So far the consensus it no strainers on the mains.

I'd love to see some pictures of the screen system on the bottom of the boat.

Do I understand this correctly, the water entry and screens are designed so that screen system is angled slightly towards the bow so while running, the water is forced up into the chest. If so does the pressure of the water have any detrimental effect on the flow of water being sent to the impellers for the mains?

[Questsportfishing]

the way that the predator 35's screens were you take them off (every year at the boat yard!!!) hand sand out the ablative paint with some 3-m pads real good... paint them back up. paint the screens inside and out and re-fasten them. keep your bottom clean and uase your boat. bottom line.

[JD5652]

F1-

Not a Carolina or custom design by any means....but my 44 Ocean does not have sea strainers or a sea chest and use only external strainers. The external strainers are wedge shaped with the flat part of the wedge facing the bow to "scoop" up more water with more speed. Same for gen set.