Hieght for bilge exit

I am hoping someone can take this picture that I have marked the approximate water level height (just looking at pictures of similar models i have seen in water as I have never had this boat in water) with a black line and give me a idea by marking it as well with a good spot to run the exit pipe from my bilge pump, all reply's and great appreciated

From what I have been able to source this boat hasn't seen the water since before 1989, the only reason I know this is our registration centers computer system only dates back that far and they have no record of boat or trailer in their system Even though my trailer has a rego plate on it still hehehe, so there are no water level marks on the hull for me to use as a guide.

Thanks again

Re: Hieght for bilge exit

I'd go as high as possible on the hull, just below the hull / cap jiont. Google Rule bilge pumps, I think their website has drawings for recommended hose routing and height. Nice looking boat!

Re: Hieght for bilge exit

You want to be well enough above the normal water line to be safe, but . . . my current boat has the bilge exit right below the swim platform . . . so it is about 6" (15 cm) above the waterline. My previous boat had the exit up near the rubrail . . . so it was about 20" (50 cm) above the waterline.

Your choice . . . :noidea:

Re: Hieght for bilge exit

Put it as high as you can. If you can't get it much above the water line of your boat then put a loop in the outlet line so any water splashing against the hull can't get back in.

Re: Hieght for bilge exit



As the others have said, as high as you can. I'd shoot for 6" below the rub rail.

You want to notice when the pump kicks on, you want to see the discharge and hear the splash of the discharging water to let you know something is going on in the bilge.

Re: Hieght for bilge exit

Nice looking boat. I put mine about where the crosshair is above and on the same side as the helm. That way I glance over my right shoulder under way and can see the water jetting out. Can't hear the pump running or water splashing. Just a thought.

Re: Hieght for bilge exit

As everybody has said the safest place is always the highest. Once water starts entering any hole in a boat it will only stay afloat as long as your battery and bilge pump last. Putting a loop in your bilge hose is a good idea to help stop water from getting back in. You can also try putting in an inline one way valve too so water can only flow out not in.

Re: Hieght for bilge exit

tazrig said:

As everybody has said the safest place is always the highest. Once water starts entering any hole in a boat it will only say afloat as long as your battery and bilge pump last. Putting a loop in your bilge hose is a good idea to help stop water from getting back in. You can also try putting in an inline one way valve too so water can only flow out not in.

Click to expand...

Some pumps are designed to only work w/ a running vertically only hose: no horizontal runs, no bends, no loops; and some won't function properly w/ a 1way valve.

Some of the Rule bilge pumps, suggested above, are the 1's where both of those apply...

Read & follow the installation methods & directions that apply to your bilge pump


EDIT: I couldn't find the Rule pump info again on their page, but it is posted on their website that some of their pumps need vertical run only hoses, and no check valves...

Re: Hieght for bilge exit

jbcurt00 said:

Some pumps are designed to only work w/ a running vertically only hose: no horizontal runs, no bends, no loops; and some won't function properly w/ a 1way valve.

Some of the Rule bilge pumps, suggested above, are the 1's where both of those apply...

Read & follow the installation methods & directions that apply to your bilge pump


EDIT: I couldn't find the Rule pump info again on their page, but it is posted on their website that some of their pumps need vertical run only hoses, and no check valves...

Click to expand...

I've always used Rule pumps with Rule float switches along with in-line check valves (usually the 1500 or 2000 GPH) and never had a problem but i'll take your word for it. Maybe on the smaller pumps they don't have enough power to push the flap open. I do agree though, always go with the manufacturers recommendations.

Re: Hieght for bilge exit

The higher the head (vertical distance to the fitting), the lower the output, as would it also be with an in-line check valve. As a practical matter, it should go where it can be easily plumbed and wouldn't be subject to immersion. I can't hear mine when the big motor is running, or see it without leaning over the gunwhale, so I have a dash light ...

Re: Hieght for bilge exit

I think it's the back pressure, if I remember correctly, and it was stated as to why no backflow valves, which as I understand them are check valves....

I'd never heard of them, so I looked them up after they were posted earlier by kjd. I just opened a random pump's info from their site, and thought, hmm, vertical hoses only & no check valves, interesting... So I remembered it.

Otherwise, yep, makers info and directions...

To compare the vert pipe to house plumbing & sump pumps, I do suspect it was an auto shut off pump. For a given pump, with a stated outflow pipe diameter, a sump pump will only push a vert column of water so far, it'll need to be pumped out the side of the house somewhere below that max lift elevation.

Using engineering that is WAY over my head, I guess the designers of the pump know what that distance is, and can set the auto shut off to occur when the weight of the water column falls below a minimum threshold, reducing the back pressure (resistance against it's impeller), when the pumps specs, outflow pipe diameter & etc are held constant.......

My amateurish explanation may not be wholly correct, but is generally accurate :cold:

Taz: I need to check, but I'm not sure I understand the vented loop to prevent siphoning that I highlighted in blue below..... Is this the 'check valve' you're using?


A vented loop w/ a duckbill 1-way valve? So not really a check valve or backflow preventer, but does those functions.

Cool, learned something again today

FOUND IT: in the Q&A section at the bottom of the Automatic Bilge Pump page....
Questions & Answers
Are the Rule bilge Pumps self priming?
Bilge pumps are not Self Priming
Can the hose run horizontally?
No......the discharge hose must run continually upwards •Reductions in hose size will reduce output
Will increasing the discharge pipe increase output?
Increases in hose size will not increase output
Does reversing polarity decrease pump capacity?
Reversed polarity runs pump at 20% capacity
Should I increase the wire gauge on long runs?
Increase wire gauge for each additional 20 foot run
Can I install a check valve on the pump discharge?
Check valves are not recommended
How do I prevent water from siphoning back?
Install a vented loop for anti-siphoning
Do the pumps have a break-in period?
Break in for 10 hours for maximum pumping
Does Rule repair the pumps?
Rule does not repair pumps - it is not cost efficient for the consumer
Can I get parts for Rule Pumps?
Rule does not sell pump parts due to liability
Why doesn't Rule Pumps want check valve on the pump's discharge?
Check valves are prohibited by the American Boat & Yacht Council for use as an anti-siphon device-and with good reason: They're notorious for failing in both the open and the closed position, which respectively leads to flooding or failure to pump. If the valve is close to the pump, the pump may not be able to overcome the weight of the water on the other side of the valve, rendering the pump ineffective.
Why does my automatic Rule Pumps turns off if I install a check valve on the discharge of the pump?
The automatic bilge pump turns on about every two and a half minutes to "check" for high water. If water causes resistance on the pump, it continues to pump until the resistance lowers. With the check valve installed at the pump, it cant feel the weight of the water, and shuts off, allowing the bilge to fill with water!
Do I need a separate switch with automatic Rule Bilge Pumps?
Through advanced electronic technology, Rule Automatic Bilge Pumps eliminate the need for a separate switch to activate the pump. Once power is supplied, starting and stopping is completely automatic. The pump checks for water every 2 ? minutes by running for a second and measuring load against the impeller. If water is present, the pump remains on until the water is removed. Thereafter it resumes its 2 ? minute check cycle. The pumps feature two positive leads, one which is automatic and one which can manually override the pump and turn it on at any time.

Re: Hieght for bilge exit

Actually, Taz, you posted that you're using float switches, so, we're talking 2 different types of pump :facepalm: It's late, the day's caffeine won't sustain me any longer......

Thanks for helping me learn something more about bilge pumps

Re: Hieght for bilge exit

jbcurt00 said:

I think it's the back pressure, if I remember correctly, and it was stated as to why no backflow valves, which as I understand them are check valves....

I'd never heard of them, so I looked them up after they were posted earlier by kjd. I just opened a random pump's info from their site, and thought, hmm, vertical hoses only & no check valves, interesting... So I remembered it.

Otherwise, yep, makers info and directions...

To compare the vert pipe to house plumbing & sump pumps, I do suspect it was an auto shut off pump. For a given pump, with a stated outflow pipe diameter, a sump pump will only push a vert column of water so far, it'll need to be pumped out the side of the house somewhere below that max lift elevation.

Using engineering that is WAY over my head, I guess the designers of the pump know what that distance is, and can set the auto shut off to occur when the weight of the water column falls below a minimum threshold, reducing the back pressure (resistance against it's impeller), when the pumps specs, outflow pipe diameter & etc are held constant.......

My amateurish explanation may not be wholly correct, but is generally accurate :cold:

Taz: I need to check, but I'm not sure I understand the vented loop to prevent siphoning that I highlighted in blue below..... Is this the 'check valve' you're using?

A vented loop w/ a duckbill 1-way valve? So not really a check valve or backflow preventer, but does those functions.

Cool, learned something again today

FOUND IT: in the Q&A section at the bottom of the Automatic Bilge Pump page....
Questions & Answers
Are the Rule bilge Pumps self priming?
Bilge pumps are not Self Priming
Can the hose run horizontally?
No......the discharge hose must run continually upwards •Reductions in hose size will reduce output
Will increasing the discharge pipe increase output?
Increases in hose size will not increase output
Does reversing polarity decrease pump capacity?
Reversed polarity runs pump at 20% capacity
Should I increase the wire gauge on long runs?
Increase wire gauge for each additional 20 foot run
Can I install a check valve on the pump discharge?
Check valves are not recommended
How do I prevent water from siphoning back?
Install a vented loop for anti-siphoning
Do the pumps have a break-in period?
Break in for 10 hours for maximum pumping
Does Rule repair the pumps?
Rule does not repair pumps - it is not cost efficient for the consumer
Can I get parts for Rule Pumps?
Rule does not sell pump parts due to liability
Why doesn't Rule Pumps want check valve on the pump's discharge?
Check valves are prohibited by the American Boat & Yacht Council for use as an anti-siphon device-and with good reason: They're notorious for failing in both the open and the closed position, which respectively leads to flooding or failure to pump. If the valve is close to the pump, the pump may not be able to overcome the weight of the water on the other side of the valve, rendering the pump ineffective.
Why does my automatic Rule Pumps turns off if I install a check valve on the discharge of the pump?
The automatic bilge pump turns on about every two and a half minutes to "check" for high water. If water causes resistance on the pump, it continues to pump until the resistance lowers. With the check valve installed at the pump, it cant feel the weight of the water, and shuts off, allowing the bilge to fill with water!
Do I need a separate switch with automatic Rule Bilge Pumps?
Through advanced electronic technology, Rule Automatic Bilge Pumps eliminate the need for a separate switch to activate the pump. Once power is supplied, starting and stopping is completely automatic. The pump checks for water every 2 ? minutes by running for a second and measuring load against the impeller. If water is present, the pump remains on until the water is removed. Thereafter it resumes its 2 ? minute check cycle. The pumps feature two positive leads, one which is automatic and one which can manually override the pump and turn it on at any time.

Click to expand...

Ok, I see what you're talking about now. I always put my check valves just before and slightly above the exit hole so any water coming back in the hole doesn't go back down the hose or hold the flapper shut. To answer your question no, that black semi circular tube is not what I use for a check valve. I use a straight piece of pipe with a check valve inside of it. I have 2 Rule pumps and one manual one. On one side of the boat the auto and manual pump share a piece of the hose that goes overboard So the check valve both helps stop water from coming back into the boat but also stops the manual pump from pumping water up one hose and back down the Rule pump hose.

Re: Hieght for bilge exit

Thanks guys I'll use the installation recommendations crossed with info here and put it all together for the end result, the info supplied didn't give a height for so i better read up some more, my bilge is a sea flow 1100 gph thanks again

Re: Hieght for bilge exit

There is no reason for a valve or a complete loop in a bilge pump line, the less rise, length of line from the pump the better. It should have a riser loop. That being said, the bilge exit should be as stated above, as high as you can get it, but you have to figure in the rise to get the proper flow that it is actually going to pump because the rise also will reduce the gph. And food for thought, the outlet/hose/through hull fittings should be sized correctly with the proper type hose. The thruhull fitting should be checked frequently to make sure mud dobbers ect have not clogged the exit. A secondary larger pump is also a very good idea wired to seperate battery circuits.

For the op's boat the 1100 gph is good for a primary, but a tleast a 2500 gph or more would be smart as a back up.

Simple diagram

Re: Hieght for bilge exit

toey77 said:

Thanks guys I'll use the installation recommendations crossed with info here and put it all together for the end result, the info supplied didn't give a height for so i better read up some more, my bilge is a sea flow 1100 gph thanks again

Click to expand...

Toey, there is no specific height to offer you. Very simply the higher you can mount the exit hole the safer and happier you will be. Just that simple.

Re: Hieght for bilge exit

tazrig said:

Toey, there is no specific height to offer you. Very simply the higher you can mount the exit hole the safer and happier you will be. Just that simple.

Click to expand...

But as Chriscraft254 said the higher you get it the more force is needed to push the water that high. All bilge pumps should have a maximum rated height for the exit from the bilge pump location or maximum rise to exit. I would go for a mid point between the water line when fully loaded and the max height for the exit, this is where it would be unlikely to get water most of the time and provide you with the least resistance to output flow.

Re: Hieght for bilge exit

chriscraft254 said:

Simple diagram

Click to expand...

Does anyone have a pic of a boat with the bilge discharge installed this low on the hull, I've never seen a real boat with one installed this low. I'm pretty sure the reason I've never seen one installed this low is because when a boat starts taking on water the stern sinks in the water which would put the discharge under water.

Bilge pumps are made to work hard, that's their job.

Re: Hieght for bilge exit

I don't have a picture, but the exit for the bilge plumbing on my boat is actually underneath the swim platform. So, it is probably about 6" above the water line at best. I'm not sure if it loops up in the engine compartment to provide greater resistance to flooding, but I can check next Monday and advise accordingly.

Re: Hieght for bilge exit

I do have a picture . . . .



See the exit port in the upper left area of the picture. It is on the inside of the swim platform abutment. Comparing it to the water line, which runs accross the top of the outdruves, it looks to be about 6" (15 cm) above the water line (at best).