Closing Cockpit Drains

Stemar

Stemar

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Jazzcat's cockpit drains are holes in the floor, with an aft-facing elbow underneath, draining directly into the sea. When things get bumpy, and we seem to find 20 knots on the nose and wind over tide far too often, waves smack the underside of the deck with monotonous regularity, and water squirts a couple of feet into the air.

I've tried sink plugs, but they just get blown out. We have some tops for part-used wine bottles (yes, we do get them chez Stemar) which are a rubber ring about 5mm wide that fit loosely into the bottle, and have a lever on top that pulls up a central bit to expand the ring, a bit like this
51rEbVEgbQL.jpg

Does such a thing exist for pipes around 1 3/4" diameter? If not, any other ideas?

Yes, I'm aware of the risk of flooding if we were pooped, but the cockpit would never get deeper than about 2 ft, so I could reach down and take 'em out, and I'd attach fluorescent flags to them, so I don't forget 'em when I leave the boat.
 
Stemar said:
Jazzcat's cockpit drains are holes in the floor, with an aft-facing elbow underneath, draining directly into the sea. When things get bumpy, and we seem to find 20 knots on the nose and wind over tide far too often, waves smack the underside of the deck with monotonous regularity, and water squirts a couple of feet into the air.

I've tried sink plugs, but they just get blown out. We have some tops for part-used wine bottles (yes, we do get them chez Stemar) which are a rubber ring about 5mm wide that fit loosely into the bottle, and have a lever on top that pulls up a central bit to expand the ring, a bit like this
51rEbVEgbQL.jpg

Does such a thing exist for pipes around 1 3/4" diameter? If not, any other ideas?

Yes, I'm aware of the risk of flooding if we were pooped, but the cockpit would never get deeper than about 2 ft, so I could reach down and take 'em out, and I'd attach fluorescent flags to them, so I don't forget 'em when I leave the boat.
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Wooden bungs trimmed to not be trip hazards?

3D printed device?

Two suction cups like this used for moving glass? Small ones are available.
 
We have a cockpit drain out the stern that occasionally back fills if things get rather too sporty on one tack.
I took a standard wooden tapered emergency seacock bung and shortened slightly. I also drilled a hole through to add a rope.
Kick it in and it stays in place for our needs, and needs the string to pull it back out.
Worth a try
 
I’ve just replaced all my boat’s skin fittings and sea cocks and have always previously had the same problem with the cockpit drains. I fitted non return valves on top of the sea cocks and it has cured any return flow. I used TruDesign throughout and they sell non return valves that suit my 1.5” sea cocks. It takes very little head to get the non return valves to open.
 
Our cockpit is low to the waterline and the drains not crossed. To save having to wear wellies in fair weather I have a couple of orange rubber bungs (from an eBay science supplies store) to stop the cockpit filling when heeling or motoring hard. I never use them if the weather gets lively.
 
Shuggy said:
I’ve just replaced all my boat’s skin fittings and sea cocks and have always previously had the same problem with the cockpit drains. I fitted non return valves on top of the sea cocks and it has cured any return flow. I used TruDesign throughout and they sell non return valves that suit my 1.5” sea cocks. It takes very little head to get the non return valves to open.
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Interesting. Would you not worry that it's one more thing to get jammed up? It's probably fine when new and clean but I would fear that years of rain and sea washing crud down the drains would lead to non return valves that one day failed to open...
 
Aquanaught said:
Dinghy expanding drain plugs might be what your looking for. Lalizas Expanding Drain Plug
Click to expand...
I was going to suggest the same. If you can’t find one to suit then I suspect it would not be rocket science to engineer a larger rubber bung to fit your wine bottle stopper which would achieve the same thing.

But if something like this would fit (I think there are cheaper this was just quite well illustrated) it would be even better: Amazon.co.uk
As you stop the water coming back up but let spray drain.

The other option is a self sealing scupper with a flap on outside.
 
dunedin said:
We have a cockpit drain out the stern that occasionally back fills if things get rather too sporty on one tack.
I took a standard wooden tapered emergency seacock bung and shortened slightly. I also drilled a hole through to add a rope.
Kick it in and it stays in place for our needs, and needs the string to pull it back out.
Worth a try
Click to expand...
I like this suggestion very much.

It's simple, cheap, and practical.
 
The cockpit drains on our South Coast One Design had ping pong balls in them in a cavity below the drain itself. Any sign of water coming up and the ping pong ball floated up and sealed the drain. There was a screw in top to enable fitting/replacing the ping pong ball.

Not sure where you’d get them now as our SCOD was built in 1959 by Camper and Nicholson. I suppose you could get a hobby machinist to make some. It would be an interesting bit of turning. You’d need some stock bronze bar…
 
john_morris_uk said:
The cockpit drains on our South Coast One Design had ping pong balls in them in a cavity below the drain itself. Any sign of water coming up and the ping pong ball floated up and sealed the drain. There was a screw in top to enable fitting/replacing the ping pong ball.

Not sure where you’d get them now as our SCOD was built in 1959 by Camper and Nicholson. I suppose you could get a hobby machinist to make some. It would be an interesting bit of turning. You’d need some stock bronze bar…
Click to expand...
You can buy ping pong ball scuppers. Might work ok for this - I’ve only experienced them on a rib where they were a bit sensitive to sand/grit/weed etc so weeped water back in to the boat.
 
Hi Stemar, what about cutting two pieces of thin supple rubber, larger than the outside drain holes in the transom, screw the top of the rubber onto the transom, so the rubber flaps will allow water to drain from the cockpit but stop any water from entering from outside. I hope this explanation makes sense. Best regards, Oz.
 
ylop said:
You can buy ping pong ball scuppers. Might work ok for this - I’ve only experienced them on a rib where they were a bit sensitive to sand/grit/weed etc so weeped water back in to the boat.
Click to expand...
Taking forward the thought of wot a rib does - have drain trunks! Large diameter flat pipe - fire hose etc when dangling free then water drains freely but they have a tie in the end to told them up to stop water backing up when stationary - like this;

Pardon our interruption...
 
Yes - but easy enough to take the hose off and check them once a year or so. At least that’s my thinking! My cockpit drain set up is horribly complicated but the cockpit is generally covered with an enclosure or a winter cover when we’re not sailing so my primary concern is making sure the only sea cocks we leave open can’t flood the boat if a hose pops off somewhere.
 
Shuggy said:
Yes - but easy enough to take the hose off and check them once a year or so. At least that’s my thinking! My cockpit drain set up is horribly complicated but the cockpit is generally covered with an enclosure or a winter cover when we’re not sailing so my primary concern is making sure the only sea cocks we leave open can’t flood the boat if a hose pops off somewhere.
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I’m always interested to hear people refer to ‘hoses popping off’. I can’t remember it ever happening. Perhaps I’ve missed the news on this?

Edit: I’m not too sure about ‘easy to take the hose off once a year.’ My experience is it’s blooming hard to get hoses off hose tails after they’ve been on a while.
 
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