Self-bailing cockpits

S

Sawdust

New member
The well-executed rescue by our C-brats brings up another topic. So here's Dusty's take.

Every self-bailing cockpit I've had - incuding Tomcat 24, Orca, Arima, Pierson, and others - only self bail under ideal conditions. My biggest problem with water coming back through the scuppers and flooding the cockpit is when tending shrimp pots. The boat always weather-cocks, stern to the seaway, with the shrimp pot acting as an anchor. We usually back up on the pot line to ease the strain on the puller which increases the water pressure on the transom. Too much weight aft, which lowers the scuppers, increases the problem.

The only good solution that I've found is a commercial unit which contains a small ball that seals the scupper with any backpressure present. It works! The other rubber flaps, etc., don't.

I don't know the vendor of the unit, but I can get it from Les if there is any interest. These little inexpensive gadgets would probably have saved the Bayliner which took on so much cockpit water it lost stability and flipped.

Dusty
 
Sounds like a great idea -- maybe should be integrated into the manufacturing process.

If you can get the manufacturer info and pass it along, I'd appreciate it...well worth whatever cost...I definitely have an aversion to water being inside the boat when it's not raining or we aren't washing the boat :-)
 
Dusty is absolutely right on.... My tug has scuppers....and when heavily loaded it would always take on just a bit of water...I often wondered how it would react in a half flooded condition...I don't think those little flaps would work in that situation.
What I did on my tug was install ball valves in the line...so I could positively close those holes.....and open them when I wanted...I still can open them when I wash the deck...or drain rain water...but most of the time I keep em closed.

Joel
 
Joel,

Great solution. The lines are very difficult to get to on some of these modern boats -- I've even made plugs to fit the inboard side. The ball valves seem to do the job, and that's the easy way. On the 22 CD I installed a second monster-sized pump, which probably isn't big enough if you really get a big one aboard. Shrimping with the 22CD with lots of wind and a "friendly" visitor with a stern wave a mile or so high can give me the chills. The older I get the chillier I get. :lol: From nervous to full blown coward in very few years.

Steve, I'll get more detail from Les on the check valves.

Shux, it would be dull out there without a challenge once in a while, eh?

Should be fishing instead of watching 35 knots of gusty wind tearing up the water out front.

Dusty
 
There are a couple brands that make the ping pong ball scuppers if that's what you are refering to, and I agree they are way better than the plastic flapper deal. I think self bailing is a good idea when it works right. My last boat was a disaster, but they ended up redisigning the hull so it worked properly. The floor really needs to have some distance from the water line to work. Especially once gallons of water have flooded your cockpit, your water line is going to change, and if you only have two inches that might not do it. On smaller boats it's hard to do since you have less room to play with in the design. It's a great feature but if it's to the point where I need it I already made a misjudgement. I'm not sure that they had an effect on the trophy sinking or not, it is just a possibility. I still need to see what they told Tom. But when I move up to a larger boat in a couple years it will have self bailing decks, luckily the CD 25 already does.

Sark
 
I changed out my rubber flap scuppers with the ping pong type BEFORE I even put my boat in the water for the first time -- due to Plan B's reports of scupper leakage! The ball type fits the same hole pattern so no drilling needed! They are available at West Marine.
http://www.westmarine.com/webapp/wc...3/0/0/scuppers/All_2/mode+matchallpartial/0/0

They work great, you'll hear them popping in and out though in choppy seas, but after awhile you tune them out -- actually a "comforting" sound when you think about it.

A larger problem though with my vintage of CD25 ('02/'03, not sure of newer models) it has 3 large openings from the cockpit deck to the bilge for cables to pass through near the transom. The cables only take up about 1/3rd or less of each opening (approx 6 inches in diameter) -- this is a major problem if you take on a large wave over the transom. I plan to seal those openings with tightly packed closed cell foam then fiberglass a removable lid over them to minimize the opening size (then screw down the lids). I figure the bilge pump will keep up with any that slowly leaks through (I also carry a fairly large manual pump).

Steve
 
On the really vintage CD 25s (mine is 1996), the drain outlet thru-hulls are below the water line. Very slow to drain unless underway. There are no scuppers on it, because they wouldn't do anything anyway.

Am I the only one who thinks that the cutaway section of the transom is a good idea? Everyone else seems to think the full transom like the CC has is better. If wave fills the back of a full height transom hull, she's going down. If a wave fills the back of a CD 25, over half of the water is falling back out. If a wave fills the back of a CD 22, nearly half is falling back out. If the full transom is such a no-brainer good idea, why are there so relatively few of them made? Sure, we can conjecture up lots of different scenarios, but if that much water was coming over the back of the boat I scarcely think an extra ten-twelve inches of freeboard in that one little spot is going to save too many butts. And after the wave passes, I think knee high in the water is better than butt high.

I don't know. I am not an engineer, but I am sure we'll be hearing from one. I just can't imagine having 90% of the OB boat manufacturers designing their boats with the lower transom if it is dangerous or stupid.
 
I have the ping pong ball scuppers and they work pretty well. One word of warning. Keep them clean! Anything that gets into them (seaweed, leaves, etc) prevents them from closing.

I think C-Dory was experimenting quite a bit on the earlier 25's. Mine was the January 03 Seattle boat show boat and it had the ping pong scuppers.

I'm not sure about the transom cut out either Mike. The one time I took water over the transom, I was off of Lopez Island backing down towards my fishing line, not paying attention to a passing tour boat. It sent a wake over the back, getting me wet, but most of it went back out the way it came. So in that case your theory won. With the transom cut out and scuppers, I didn't even hear the bilge pump come on.

When I read thehulltruth.com, the guys that are backing down on Marlin and big yellow fin tuna have to deal with this a fair amount. They're 50 miles out with some big waves that occasionally wash over the back. Consensus is that the only solution is to hit the power and get the boat up on a plane so that you can get the water out the back. However, their scuppers usually are huge, as are their motors. Their biggest fear is losing power.
 
TyBoo":2emd8c2r said:
Am I the only one who thinks that the cutaway section of the transom is a good idea? Everyone else seems to think the full transom like the CC has is better. If wave fills the back of a full height transom hull, she's going down. If a wave fills the back of a CD 25, over half of the water is falling back out. If a wave fills the back of a CD 22, nearly half is falling back out. If the full transom is such a no-brainer good idea, why are there so relatively few of them made? Sure, we can conjecture up lots of different scenarios, but if that much water was coming over the back of the boat I scarcely think an extra ten-twelve inches of freeboard in that one little spot is going to save too many butts. And after the wave passes, I think knee high in the water is better than butt high.

I don't know. I am not an engineer, but I am sure we'll be hearing from one. I just can't imagine having 90% of the OB boat manufacturers designing their boats with the lower transom if it is dangerous or stupid.
Click to expand...

Mike,

While I did put in a transom board, I've been thinking about this for awhile and I think I'm starting to agree with you. The rescue thread obviously brought this to the fore again but this event's a prime example of the most common way that boats capsize - e.g. they actually flounder first and then capsize later. After learning about this a year or two ago, and reading a bit on the web, I made sure to add another bilge pump and put in a transom board. The discussion of transom boards got hashed over a bit last year when the CD25 was swamped in Cook Inlet. It was around then that I added the second bilge pump and transom board.

However, the thing that always worries me is loss of battery power to the bilge due to a switch or the battery terminals getting flooded. While I agree with DoD Dan's comments in the earlier thread that if one fills the cockpit of a 22 with water you're in BIG trouble (I believe his words were "toast"), I also note that the lower portion of the transom cut-out is below the level where my battery switch and terminal are. Hence, under ideal conditions (which rarely exist in actual experience), if one filled only the cockpit to the lower portion of the cut-out due to a rogue wave but was otherwise in calm seas (as might happen from passing wake), the battery would stay above the water and perhaps, just maybe, the bilge would empty things back out.

I'm still thinking about adding another bilge pump that is powered off of a separate battery that is sealed to all water. I haven't figured out how to accomplish this but I think with
1) proper gas venting (perhaps through a gas but not water permeable membrane or a 1-way valve),
2) two wires in from the charger with inline diodes so that the battery could be charged but not leak to ground if the charger goes under water and
3) sealed wires to the bilge pump
it would be possible to have a system that would continue functioning even if the battery was temporarily wet.

I think this might be useful even when one doesn't take a lot of water into the cockpit as the current hatches over the lazarettes where my batteries are stored are not that water tight. Hence, I think that it would be possible to lose battery power without filling the cockpit. What have others done to provide an independently powered bilge?

As an aside, I've also been toying with an idea that would be like air bags concealed under a rub-rail like mounting near the chines. I thought this might be a way to create something that could be depoyed in such events to lift and hold the cockpit up so the bilge pumps could work and to keep the boat from turning over. I thought it was a bit of a crazy idea but I did do a patent search and found that at least I wasn't the first crazy person to think of this.

In practice this would probably be too expensive or too ugly to be practical so I continue to focus on keeping me and my boat out of trouble in the first place.
 
Several years ago when we had the 16' Cruiser, we hit some "heavy wave action" between Everett and Hat Island. Fortunately, I had the camperback deployed and I know that that kept a lot of water out of the cockpit! One wave hit the side of the boat and about 5 gallons of water managed to sneak through the camperback snaps on the side. Obviously, you'd have to have the camperback in place before that "rogue wave" hit you. (Fairly easy for us "cruisers" to keep a camperback on in "marginal" sea conditions, but not conducive at all for you guys trying to fish from the cockpit). (Additionally, a camperback could rip loose in a "bad wave hit", so it isn't a "foolproof" solution).
 
Well, here's a thought on self bailing cockpits. Our first experience was crossing the Pacific between Mexico and the Marquises. The boat (36' sail) had an open transom. In the trade winds, when the waves would come over the side, the open transom would let the water right out. Same for a breaking wave over the rear. It would happen so fast, there was no time to worry.

Now, the CD 25 drains are only there to let out drainwater: they're about 2" in diameter, and have very little pitch. One has to count on the aft bilge pump. On the 25, the batteries are tucked up under that transom, and I hope I never find out if it works with the cockpit full.

As for the transom, it's a two level affair. Where the outboard mounts is lower, and the wave will break into the trough there ( I hope,) with the higher transom between the outboard mound and cockpit blocking the broken wave. At any rate it's theory, and again, I hope I never put it to the test.

My question is why the factory puts the drains in the outboard trough a even inch above the floor of that trough. You always have an inch of water there. I filled that space with boards, but it would have been easier for C-dory to drill those holes an inch lower.

Boris
 
I'm soaking up all the info this idea popped in my head. Put a bar (raised if you like) on the rails and get some long rubber, mudflaps - or whatever - to hang down on the transom. Or maybe a board on a rod so it swivels if the flaps can't hold back the water. You could fashon some light springs to keep it from clanking around. Either way it stays closed against the transom when a wave hits, and swings out toward the motor to release the water. I'm going by just the pictures I have of a real live boat. :embarrased
 
Hi Boris,

Mine on my '03 are exactly at the level of the rear-recessed trough. So the trough is always wet but no collecting water. I wouldn't see the harm in that inch of water though, it stays back there doesn't it in the trough? Water will come in and out all day, very small amount, but it stays back there in the last 5-6" hidden up against the transom. I changed out my rubber flaps right away for ping pong ball types, now they click in a chop at rest, sometimes a little annoying while in the cockpit.
 
The factory puts the drains an inch above the floor of the trough to prevent or minimize potential gas leakage from going overboard. It may even be a regulation nowadays. One is supposed to keep the trough reasonably empty of water to accomplish this. We consider emptying the trough just part of good boat house keeping at the end of the day.
 
This is a very interesting discussion. On my 27' the self bailing holes are on the side. They are about 4" in diameter and have nothing covering them. The cockpit floor has a very pronounced camber to push the water towards the "drains". Looking at this picture I fould a while back of a guy fishing in Alaska on a 27' it looks like they are a few inches above waterline too. Time will tell how well this system works out for me.

Workin4.jpg
 
Interesting on the 1 inch above the cockpit floor purpose, sounds like one of those "half-vast" efforts if true.

Boris, you wrote
Now, the CD 25 drains are only there to let out drainwater: they're about 2" in diameter, and have very little pitch. One has to count on the aft bilge pump. On the 25, the batteries are tucked up under that transom, and I hope I never find out if it works with the cockpit full.
Click to expand...
Once the 4 access holes from the cockpit deck to bilge area are closed up on my boat (don't know if yours has them), there really isn't anyway for a substantial amount of water to get to the bilge area except what leaks past the closed hatch covers. The 500-1000 gph bilge pump behind the gas tank should easily take care of the small amount of water that gets into that area. The water on top of the cockpit will eventually run out the 2 scuppers. Am I missing something?
 
Transom door! yay! Maybe that little door in the C-Ranger 25 is a good idea after all. It bars splashes and small waves from the cockpit, but would prob pop open (if not locked) if a large amount flooded in. John
 
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