Water coming in through bilge pump

[BillWilliams]

Our Formula will allow water to come in through the bilge pump if there's a good force of water against the stern (reversing hard or coming off plane fast).

The outlet for the pump is the smaller hole to aft on the right side in the picture. You can see how the design of the hull is the water gets trapped in the outdrive area and would allow it to enter the hole.

The hose does have a loop going higher than the hole to cut down on water coming in. I have about 3 or 4 inches above the top of the loop so I was wondering if you folks thought it would help to purchase a longer hose and make the loop taller? I kind of figure if there's enough water hitting the transom area, it would still come in so I don't want to waste my time (and money) on that if others agree.

Another thought I had was to move the bilge outlet to the side of of the boat higher up but these are currently the only outlets in the hull so the hull is nice and clean from that perspective.

Overall, it's not a big deal but I'm one of those who like a nice, dry bilge.

Thanks

 

[Thalasso]

The discharge should be above the water line.
You sure they are bilge pump outlets beings there is another one on the other side
Does your hoses have a syphon breaker, with the vent fitted up high above the waterline?

 

[BillWilliams]

The two discharges with flaps are floor drains and the hole on left side towards the aft is for the sink. When the boat is sitting, the waterline is just at or just below the u-bolt in the gimbal ring for the swivel pin.

The hose simply has a loop in it higher than the discharge. No other devices are on the hose.

 

[JimS123]

I never had a boat with a bilge pump discharge that was NOT on the side of the boat. Seems like a bad design to me.

If it were me I would put a check valve in the line.

Regardless, I would also make a call to Formula and see what they had to say.

 

[airshot]

All my boats ( many of them) over the years, always had bilge discharge on the sides !! With that said, if it were my boat, I would try a taller loop ( easiest and cheapest) and see what happens, if that doesn't work then add a check valve into the line...

 

[BillWilliams]

I've always heard a check valve in a bilge pump discharge is problematic.

 

[04fxdwgi25]

I've always heard a check valve in a bilge pump discharge is problematic.

Could be a problem if debris was in the line and it got plugged up..
Some pumps have them built in. I know the one I installed in a small boat did. don't recall the name.

 

[tpenfield]

I'd just go with a longer hose to get a taller loop and see how that goes.

Not sure a check valve for a bilge pump line is the best thing, as Murphy's law will prevail.

 

[dubs283]

Formula likes to keep the hull sides clean and free of through hulls. Even the galley and head sink drains route to a sump box that discharges under the swim step at the transom on bigger formulas

Great idea for clean lines but bad idea for figuring things out. Once you know it's better but the first time I dealt with a 330 ss it was a little baffling

Best bet is to install a check valve in the output of the pump. Yes there is a chance for clogging but it'll alleviate your issue.

Good part is you know about the issue and can monitor it. Very unlikely wake wash coming off step will sink your boat through the bilge discharge but if it bothers you that much a check valve/duck bill is the best solution

You could go as far as installing a through hull that has a flapper in it like the scupper drains, that would alleviate the need for a check valve in line

 

[BillWilliams]

Thank you everyone for the ideas. I'll probably just start with a longer hose and taller loop.

 

[airshot]

I've always heard a check valve in a bilge pump discharge is problematic.

Yes, but if the owner does not want to create a hole in the side of his boat, he is running out of options...

 

[04fxdwgi25]

Good part is you know about the issue and can monitor it. Very unlikely wake wash coming off step will sink your boat through the bilge discharge but if it bothers you that much a check valve/duck bill is the best solution

You could go as far as installing a through hull that has a flapper in it like the scupper drains, that would alleviate the need for a check valve in line

That is a great idea...

He could do that on all those discharge fittings.