bilge pump hose q's

[jssailem]

I ask Fred because you can see the water line. The line appears about 2-3 inches beneath the line of your bottom paint line around the boat. My boat is the one on the left in the image. You can see the 2 scupper, exhaust and bilge thru hulls across the transom.

 

[Capt jgw]

The short run is necessary. When I got my current boat the 1 1/2" bilge pump hose ran to the transom and held about 2 gallons of water. When the pump stopped running that two gallons would run back to the bilge and was enough to restart the pump. It would pump that same two gallons back and forth all day long. I added a small pump with a 3/4" hose and ran it the shortest run possible which was out the side about amidships. That hose only holds a few ounces and the back flow is not enough to restart the pump. I also raised the float switch for the big pump about 4 inches above the bottom of the bilge. The little pump handles all the nuisance water and the big pump will only come on with major flooding. No more cycling.