Gemlux Thruhull Duckbill Scupper
 

Anybody use these to plumb the scuppers out the back through the transom?

Thinking about trying this to eliminate the through the deck scuppers. Anybody try this with success? Looks like I could gain an inch if I fill in the pocket even with the gutters. Pics to follow.

I dont understand the hate for the thru deck scuppers. I like them on my Sceptre. They work great. Much better than the through the transom ones on my aquasport. I see a lot of people looking to change them, so there must be a reason.

Yea I’ve used them through the transom on my last boat with the duckbills and they worked great. I never had water come back in those scuppers at all, drained very well.

Could you provide a source for the "duckbills"?

I am debating the exact same thing now for my 23 rebuild. I purchased a set of the Gemlux thruhulls with the duckbill inserts for my boat. I was going to install them but noticed that I would have to mount them almost below the water line, in-order to get them to work at my stock floor height. The problem is the 14 degree transom angle, You have to mount the thruhull lower in order to insure the barbed tail is level with the floor height. I was not sure how effective they were going to be with keeping water out and started looking at other options. Also make sure to check for trim tab clearance.

I attached a picture of a diagram someone else draw to help explain. I purchased the longer 4.5in model. Looking back the shorter 2.5in model would have been better to help keep the fitting higher above the water. The barbed tail end has to be floor level for it to drain properly.

http://www.gemlux.com/catalog/Forged-Thru-Hulls

external mounted https://thmarinesupplies.com/products/duck-bill-scupper

I agree. I think draining water out thru the deck might be the best option for a stock floor height. No fittings or hose to fail, simple design. The only draw back to this is you cannot add a check valve to stop water flow back inside of the boat. Most likely why people try to re-rout them out the back of the boat.

Thank you for that.

That's very similar to the one's on my 78 Seafari originally. They always worked fine for me.

Here are a couple pictures that may help show how I plan to do this. I'm going to glass a piece of 1-1/2" fiberglass tube to the rear pocket and connect that to the thruhull with a short piece of hose.

I thought about using the shorter 2-1/2 thruhull but I didn't think it would be long enough by the time you put the nut and pipe connector on it.

My center console has twin I/O's so it's a bit stern heavy. I dont hate the thru deck scuppers but it sure would be nice to be able to use the boat without the plugs in and not have water coming in the boat.

What if you did it this way?

Yes that is how my deck drain is proposed to be routed out the transom from the floor. Still looks like the Gemlux thruhull fitting, will have to be mounted lower then I would like for it to work. It does not matter if you trailer your boat, but mine will have to stay in the water 5 months out of the year. I don't want the fitting to be constantly submerged in water for that long.

Please post pictures of your install. I'm very interested to see the final height of the fitting, once installed on the transom in relationship to the water line of your boat.

I agree, I’m hopeful that the’ll end up just above the waterline as I’d like to be able to leave the boat in the water on occasion and not have to worry about filling up with water if it rains. I’m going to put the boat in the water tomorrow and mark the waterline. I still have the thru deck scuppers so I should be able to make some comparisons between the waterline on the transom v/s the scuppers to see how much height I have. I’ll post some pics and results once I get it all together.

Going to get ugly when you reverse. If you’re not raising the deck and you want dry feet you can always add holes to drain into the bilge. As long as you have plugs for them they work great. I know some will think it is a sin to drain into the bilge but I did it for years with no issues on two different boats. With two good pumps there is no amount of water that can come down 2 one inch holes the pumps won’t clear.

I used the Gemlux on my 23' rebuild. Never wet feet even without raising the deck. They were always above the waterline. Plumbed like Nate's drawing. I'm sure the bracket helped when in reverse.

I drain outnof the side

I have the exact setup as Capt Chuck. same gemlux flapper same hole locale. deck not raised, armstrong bracket full float type not the skinny minny (made for twins with a single i think). cut that hole height exactly like Chuck. if was me, id move the hole cut in earlier pic to what chuck pic has. drain out transom gravity works nicer.

now with a 200lb guy in the corner a little water. fill the livewell tank behind the leaning post, same dude in corner, yeah water comes in corner a bit more. the key is it self drains at rest.

personally draining into the bilge for the deck is a no go. i have dual pumps, and occasionally can get clogged when scales get in there or a piece of potter putty knocks loose. then its a battery question when pump runs, and how long pump will run... and say a rain storm hits and boats on a mooring...for me its peace of mind i want to know that self bails at rest is all.

i may grab a duck scupper just to see, its cheap. not sure the effort to get out my existing gemlux flapper scapper is worth it, but for 15 bucks why not look.