bilge pumps

I converted my inboard boat to a outboard transom complete with a splashwell, that leaves me five compartments lengthwise below the floor. They are separated by two stringers and a middle splashwell support off the floor and are accessible at the transom. My issue is I don't want scupper holes in my stringers and splashwell support, so I'd only need 1 bilge pump. I'm wondering if a single pump on each side could handle a suction hose tee'd off two compartments so I'd only need 2 pumps. Original plan was 4 individual pumps off each compartment. anyone got a plumbing idea to keep things simple, and no I don't want holes in my stringers.

 

Will not work, unless both compartments have the same amount of water in them, which leads you back to the necessity of limber holes.
Two bilge pumps will work.
A diaphragm pump with selector valves would work.

 

A limber is the way to go; buy a small bit of epoxy and glass it all up. 4 pumps is nonsense and the pump will not work that way without float switches

 

I build limber holes into the stringers with bits of PVC pipe gooped in with a compatible putty.
Best to add the limber holes before the stringers are glassed in, so a half pipe can be used and the bottom remains flush with the hull, allowing complete drainage.

 

Everything is glassed. And I have done the pvc pipe thing through the stringers before, looks like I will be again.

 

Having a bilge pump on both sides of the boat, one to each of the two compartments via a tee, is a very good solution, as it makes your pump system a lot simpler while still being efficient in discharging the water. Take note of the pump you select, as it should be able to handle both compartments' combined volume, and you can also add install check valves to stop the backflow. Furthermore, make certain that the hoses are properly sized and placed on the path of least resistance, which can cause variations in the flow rate. By this method, you can have such a neat system in place that no scupper holes are required and the stringers and splashwell support will remain intact.

 

As kapnD stated it in post #2. The minute one hose draws air, loses suction, the pump will not pump water out of the other compartment