Cockpit drains thru bottom of hull?!

[robert sailor]

If your drain sizes are adequate then under water drains work just fine. When you are sailing the water drains much faster than if you are just sitting still.

[mlydon]

It doesn’t make a difference where the drain exits - the water in the hose will stay full to the waterline. When you add water (via the cockpit), that water displaces the water in the hose, pushing it down into the sea. What WILL make a difference is if the hose has a lot of turns - that adds resistance....

[Kayakeur]

Lots of great replies. Thank you.

I've read that when a drain is under the water line that the boat moving creates a suction that pulls water out faster. (?) I did have her on the water - Lake Michigan - and drainage was not an issue through several major rainstorms. I could test when back on the water; block the drain & dump in a bunch of buckets, open drain and time it.

Blockage, debris and mussels: I run a plumbing snake through the hose Spring and Fall, and spray garden hose through, and dig out growth. pita

In the meantime, I will keep the existing 2" drain going thru bottom of hull but replace it with new hose and clamps, as the PO had it all wrapped in electrical tape. As for 3.23.3, easy accessibility, sure, it's only a crawl 7 feet in a 2ft x 2ft space but there is room to move arms and shoulders back there, better to do it now out of the water than a mile offshore down in there water gushing in.

sanibel: With 2 in cockpit plus outboard plus stowage the place for transom cockpit drain exit will be above waterline; with a 3rd adult it may be marginal but wouldn't siphon in. Never had more than 2 adults in cockpit.

coopec; thanks, that's a bunch of good solid info.

DonCL: some good points and you're right I won't be out in huge waves. However a sistership was sunk by knockdown in a few minutes. Venture of Newport although good in light air, is tender.

ttex: one can test water flow down into water vs down into air (bucket, hose, inverted bottomless bottle); I think it flows a lot faster down into air, e.g. a drain port above waterline.

Bilge pumps: 3: 1 electric 1", 1 manual 1", hoses from bilge to cockpit, and a 1.25" hand-held barrel pump. It seems to me that the automatic electric 1" is nice to pick up small quantities, perhaps rainwater but there ought to be a more robust-ass pump. Any good brands to recommend?

And is that "accordion" type hose good for bilges?



______________________

If it ain't broken, don't fix it. Luddite Kayakeur Kahuna Bud, Virginia

[Don C L]

Originally Posted by Kayakeur

DonCL: some good points and you're right I won't be out in huge waves. However a sistership was sunk by knockdown in a few minutes. Venture of Newport although good in light air, is tender.



If it ain't broken, don't fix it. Luddite Kayakeur Kahuna Bud, Virginia

I suspect the boat sank because water was able to enter the cabin in the knockdown. Either the water came in over the side or the bridge deck is so low that a flooded cockpit allows water into the cabin. Flooding the cockpit should never flood the boat, but there are many boats where that is the case, amazingly enough.

[Kayakeur]

Originally Posted by Don C L

I suspect the boat sank because water was able to enter the cabin in the knockdown. Either the water came in over the side or the bridge deck is so low that a flooded cockpit allows water into the cabin. Flooding the cockpit should never flood the boat, but there are many boats where that is the case, amazingly enough.

Flooding during knockdown was thru companionway, & mast went more than 90 degrees, there were 2 children and a dog, I wasn't there. Should be a way to make sure hatch board stays in place. After the knockdown PO installed downhauls x3 & 3 reefs but I'll seriously upgrade pumps. One of you recommended Trident hoses - they look great on website and also as conduits for wires.
Batteries are down in the bilge so aren't they likely to short out? Surely their connections can be sealed? And the beautiful fuse panel is at most 15" above floor with it's 15-20 wires to short (but bilge pumps bypass main breaker).
All these things noticed from cockpit drain, gee some gotta go back burner

[sanibel sailor]

corrugated hose, while easier to place in position, has higher resistance than smooth. Most electric bilge pumps are centrifugal pumps which are very sensitive to backpressure- including both internal hose resistance from ribs and sharp bends, as well as head- how high the outlet or highest point in the discharge line is.


Smaller boats generally need bigger bilge pumps as a similar size hole fills a smaller boat faster. Fastest is a bucket, especially on a small boat. That doesn't help if there is an active leak, as you need time to locate and fix the source, which you cannot do if you are actively bailing.

[and4ew]

My Contessa 26 drains are like this. Only issue I had is that when there were a lot of people in the cockpit the drains were occasionally below the waterline so I'd get a bit of water slosh in. Seems like a lot of work to glass and move them to the back but I do know of at least one Co26 owner who did that.

I've thought it might be useful to have a little hood over the through hull that would create a bit of suction while underway. Never did it though and now have a different boat.


Side note: my Contessa is for sale if anyone is looking for one. Halifax, Nova Scotia. USD$4k

[j-hood]

The scuppers in the cockpit of my 1967 Rawson 30 drain straight down. Dive the through hulls every now and again. Maintain the hoses as you would tires on an airplane — change them before they need it. I can drain a mountain of water in nothing flat, no shallow pitch for any solids to collect (you will have solids). Advantages and disadvantages to everything. So it goes. But I love how mine are configured. A fair question. But below the waterline is not "wrong" per se.

Now about that bilge pump discharge... That's a different matter altogether! Shouldn't be that hard to fix. I would never allow that on Ave del Mar.

Cheers. Stay curious.

[Kayakeur]

[QUOTE Cheers. Stay curious. QUOTE]

ok, I'm staying curious.

Installing bilge pumps, wondering about electrical supply shorting out.

First, I assume a bilge pump can be totally submerged.

My electrical panel is only 12" above bottom of bilge, so could short out with not much water aboard especially with slosh.

I could wire pumps direct to battery, eh? Dead AGM battery is in bow, posts are bare, so I would put bilge pump wires onto battery and seal the connections and I guess seal in their own fuses.

Current 800gph pump is wired through panel but hot straight to pump but I assume would short out at vulnerable panel.

Installing 1 or 2 1000gph plus existing 800gph is 2800gph (45 GPMin). That's a lot but will it short out? What do y'all do? Thx