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post #1 of 14 Old 03-27-2012 Thread Starter
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Cockpit drain question

Ive been posting a lot of questions lately. This boat i am working on, the cockpit drains route to thru hulls below the cockpit rather than to the transom. It's a Westerly Cirrus. It does have a nice, deep cockpit, but the sole of the cockpit is still at least 4 or 5 inches above waterline. What might be the design reason to route the drains this way?
I was thinking gravity, needing to give enough vertical space to allow the water to drain.
Reason I'm asking is twofold. I don't like having to leave two seacocks open to let the cockpit drain rainwater, and they really aren't big enough so I thought about enlarging them but don't want to drill a hole in the hull, was thinking about adding a third drain instead, leading to the transom.
But I'm no marine architect, or pretend to be so anyone who knows a lot about this type of thing I would love to hear from

Last edited by benajah; 03-27-2012 at 12:56 AM.
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post #2 of 14 Old 03-27-2012
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Re: Cockpit drain question

I'd worry that in a following sea water would come in thru a transom fitting. The thru-hulls are the standard way to route cockpit drains from my limited experience.
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post #3 of 14 Old 03-27-2012
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Re: Cockpit drain question

If the cockpit sole is truly 4-5 inches above the (travelling) waterline then thru-transom drains may work well. It's actually quite rare for following seas to climb into the cockpit, but if the stern wave rises enough it's possible that you'll back flood that way (though that would already be happening if that was the case)

In any event you could add little flaps on the outside of the transom drains to discourage that. If you have the space and clear routing for draining out the back it may well be a viable option. Just make there there are no low spots in the system that will sit stagnant and grow weird biological cultures all year long.
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post #4 of 14 Old 03-27-2012
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Re: Cockpit drain question

There are thru hulls with scupper flaps available from various sources.
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post #5 of 14 Old 03-27-2012
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Re: Cockpit drain question

I think that before reengineering the cockpit drains, I would fill the cockpit with water and see how long it takes to drain. If that is more than 4 to 5 minutes, and you are going off shore then "more better" might be in order.
Westerlys are pretty robust boats built for the harsh conditions around England and one would hope that they have addressed this issue adequately.
During hurricane briefings here, the marina superintendent recommends that all transom aperatures be plugged with nerf balls as boats tied to piers will take waves washing upon their transoms and that sea water will be forced into any exhausts, vents etc., so adding a drain to the transom might be problematic.
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post #6 of 14 Old 03-27-2012
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Re: Cockpit drain question

As Faster said flaps solve the water in problem.

Many cockpit drains are crossed under the cockpit as when heeled the lee one may be below water level otherwise, and they work well.

If it drains slowly an additional one may be installed in the transom, but I would keep the 2 originals.

I believe the op is in San Francisco and it is not in the hurricane belt.

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post #7 of 14 Old 03-27-2012
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Re: Cockpit drain question

Has anyone ever installed an emergency cockpit bilge pump? My emergency manual one shifts a lot of water quickly, so do some electric bilge pumps.

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post #8 of 14 Old 03-27-2012
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Re: Cockpit drain question

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Originally Posted by MarkSF View Post
Has anyone ever installed an emergency cockpit bilge pump? My emergency manual one shifts a lot of water quickly, so do some electric bilge pumps.
No real reason to when you can let gravity work for you.

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post #9 of 14 Old 03-27-2012 Thread Starter
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Quote:
Originally Posted by mitiempo View Post
As Faster said flaps solve the water in problem.

Many cockpit drains are crossed under the cockpit as when heeled the lee one may be below water level otherwise, and they work well.

If it drains slowly an additional one may be installed in the transom, but I would keep the 2 originals.

I believe the op is in San Francisco and it is not in the hurricane belt.
I'm hauling it out this coming Friday for paint and keel inspection. They drain slower than they look like they should so I'll try snaking them and see if they have debris
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post #10 of 14 Old 03-28-2012
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Re: Cockpit drain question

Just to give you some ideas of the numbers from another boat, the Catalina Direct site said (if I remember correctly) that by installing a couple 1.5 inch drains, the C22 cockpit went from drain time of 12 minutes to 2 minutes. If your cockpit is proportionally small compared to the displacement of the boat, maybe that wouldn't be as much of a concern (unless off-shore).
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