The bottom photo looks like cockpit drains (make sure you clean all those leaves out), which are open all the time to allow water to drain out of the cockpit. But you say they lead to the bilge rather than outside the boat? That confuses me.

For the top picture you'll have to trace them into your boat to see where they end up. One of the thru hulls in the top photo may go to the engine, which needs to be open while underway if the engine is raw-water cooled like mine. There would be a valve near your engine to close it when you're off the boat.

On my boat we also have a thru hull from the galley sink. We have a valve under the sink which closes it.

 

If the top picture really is of two "threaded drains" then I'd say they need to be closed, hence the threads. I'm not the most visual person, but looks like these are definitely below the water line, and if they're not part of an intake set-up, then they will be if not plugged. If I'm not looking correctly then ignore me all together......most people do anyway.

I'd also recommend getting the ring of the right drain in the bottom picture to match the one on the left. If not, you'll eventually see that area of the cockpit deck delaminate from water intrusion.

 

I would think there is an outboard and not an inboard engine.

If the cockpit sole is above the waterline and there are hoses between the through hulls and the fittings in the cockpit they can be left open when sailing like on most any larger boat. If the cockpit sole is above the waterline and there are not any hoses connecting the through hulls there should be - double clamped for safety.

I agree with emoney the right drain should be changed as the left one is and sealed properly to protect any core.

 

Presumably the cockpit floor is above the water line while sailing. If so, then the cockpit scuppers should be open while sailing. You need some way to drain the cockpit quickly if you take a wave over the stern. You also need to be able to drain rain water out of the cockpit while you are away. Inspect the tubes closely to make sure they are sound. We have had a few boats nearby go to the bottom on their mooring b/c of leaking scuppers.

 

The drains in the cockpit look like stainless steel kitchen sink drains, don't laugh cause many builders source landbased alternatives, especially on older/smaller/cheaper boats. Why not change them both, put new backers under the tightening nut and you can sleep at night knowing nothing is rotting away. If the two identical drains on the hull are in the same area as two scuppers you need houses (see if you have room to connect port scupper to stbd drain/stbd scupper to port drain, may need an elbow on each but it should prevent syphoning), and definitely add shut off valves. Simple boats call for simple solutions

 

Thanks! I think I have about 6" to 1' between the cockpit drains and the hull drains. I'll see if I can get access to them. I thought the one fitted cockpit drain looked like a sink drain myself. In fact, I thought of replacing the missing drain with a sink drain! Good to know that those are not unusual in small boats. Thank you for your reply! I'm hoping to hear from someone eventually who knows what the original equipment/setup was.

 

A good alternative to the hoses sometimes can be excess radiator hoses made for
cars. With a good ss clamp, they hold up quite well while being a little flexible, but
with rigidity for the long haul.

 

Hi Donna,
The port cockpit drain connects to the port thru hull drain with a rubber hose. Haven't gotten to the starboard drain yet. - phil

 

I have those same scupper drains in my Cal. They are, indeed, sink drains. And and I can't find them anywhere. One of them is giving me fits because the it had no backing nut and applying 5200 isn't enough to hold it in place with the hose connected. So, I've plugged it temporarily until I can find a replacement. I'm considering these:
Perko Bronze Scuppers

You will have to grind the opening to allow for the flange to mount flush.

 

In order for these drains to function well when sailing the port drain should be connected to the starboard through hull and the starboard to port, as Rugosa noted in post #6.

 

Hmm..pricey little buggers! I'm wondering if an RV equipment place might have smaller drains than what might be found in a hardware store? I haven't measured my drains yet to see what size I might need. One post suggested crossing the pipes to the drains to the opposite side thru hulls, but if I do that, I wonder what will drain the bilge area of the boat? any thoughts? I have a hand bailer with a hose that looks like it might have been attached, but I'm not sure to what. Thanks!

 

I'm not sure what you mean by the bilge area of the boat.

If the drain hoses are not crossed the leeward drain can allow the cockpit to fill when heeled on some boats. Crossing them prevents this.

 

Thanks. If these two cockpit drains are cross-connected to the through hull drains, what drains the bilge/lowest area of the boat? An auto bilge pump? Or is there a drain I'm missing? It's hard to believe that the pupose of the thru hull drains are just to drain the cockpit area alone. Any thoughts? Sorry, but I'm new to this, obviously.

 

Thanks. If these two cockpit drains are cross-connected to the through hull drains, what drains the bilge/lowest area of the boat? An auto bilge pump?

Yes, a bilge pump. It isn't common to have drains in the bottom of the boat for the bilge, even though they might seem really handy on a trailerable boat. I used to let the self-bailers drain my Wayfarer. I could just hose out the entire bilge area and watch the dirty water pour out of the self bailers. Unfortunately I also launched the boat a couple of times with the bailers open and nearly sank it.

Trailerable and non-trailerable have different requirements here.

For non-trailerable boats, the aim is to have the least possible chance of a leak that could sink the boat. Hence all through hulls are connected with seacocks to shut them off, the drains are connected to through-hulls via seacocks so that the cockpit can be drained without any chance of filling the bilge, and so on. The bilge is a sealed area that is only pumped out by the bilge pump.

I think your boat is in the size range where some people might keep it on a trailer, and some at the dock. Hence it was built to be left on a dock.

 

The bilge area under the cockpit well is below the waterline - it will not drain and a bilge pump will take care of it. If the cockpit well does not drain to the bilge (it shouldn't) and the drain fittings we are discussing are sealed properly there should not be water in the bilge in normal circumstances.

 

There's about 6-8 inches between the cockpit floor (sole?) and drains and the thru hull drains. One for sure, is connected directly to the drain with a rubber hose and two clamps. I get some water in the bottom of the hull from rain, etc. behind the current thru hull drains. I was assuming that the bottom hull of the boat where the thru hull drains are is the 'lowest point' of the boat, and thereby also collect in leakage, condendation etc. which then drains out. Maybe the whole hull interior should be (ideally) always dry, so any hull drains aren't' needed except for the cockpit? Does that sound right? I'm new to this--on smaller boats I had a bailer which I would flip open to drain the cockpit while sailing, and then close down again.

 

Small sailing dinghies have bailers but larger boats don't. With a hull that is in rather than on the water it is designed to drain the above waterline cockpit well through the fittings in this thread. The lower bilge is taken care of with a bilge pump, either electric or probably manual in your case.

 

Always better to go with the real deal marine fittings, especially if in salt location, if $$$ is tight look for a RV or bar sink drain assembly as they should be cheaper. You have two cockpit sole holes/drains each of which must be connected to a thru hull, you should also have manual and/or electric bilge pump to service the bilge area. Area below cockpit sole likely getting water from disconnected scuppers and/or deck leaks. Every hole is potential water access. Sooner or later all deck fittings need to be rebedded. Hope this helps.

 

That's interesting about criss-crossing the hoses. It makes sense. Now I'm going to look at the scupper drains with the 90 degree hose connection.

 

Caveat is that unless the through hulls are far enough below the water line, when heeled the water will often have to go uphill to make it out the other side, so will pool in the low side of the cockpit.

Most people that I know who cross the hoses do so because of difficulty in getting the correct length hose in to provide for double clamping, something you can get around easily if the drains are 'bolt in' like the perko scuppers linked earlier. Install the hose with the scuppers removed, then slip the clamps and lock ring in, grease up the scupper end and insert it into the hose, when close install the proper bedding, and tighten up the ring and clamps. Others rebuild the system so the drains are plumbed aft and exit through the overhang or transom, which is my method, I try to eliminate as many through hulls as I can, nothing wrong with a properly installed and maintained through hull, I simply prefer having as few as possible.

 

Thanks for the information. It gives me a better idea of what needs to be there.

 

Merc

Whether the drains are crossed or not depends on the hull depth under the cockpit and the depth of the cockpit well relative to the waterline. On many boats if not crossed the leeward drain becomes an intake at a given amount of heel, particularly those with cockpit wells close to the waterline.

 

i have a 78 rk21....the scuppers in the cockpit are only to drain the cockpit floor....yu lowest point in you boat is right before the center table ...yes that is true....if you put water in it it will go to that point......My name is skip and i restored one also.....got some pic if you need to see how things are......hope this helps

 

The idea setup would be : Groco or similar quality bronze seacocks in the hull. Connect to the cockpit scuppers with quality, re-inforced hose. The reason being, if the hose fails while the boat is in the water and the seacocks are open, the boat will sink.

See here :

BoatUS BoatTECH Guides: Marine Hose

 

on a rk21 there isnt enough room to do that...i usee 3m 5200 very liberal on the underside with bronze thru hulls...with very thick 2 inch hose....