Post 42’ bilge pump “philosophy”

I'm not sure how the 42' is set up but on my 50', the two plugged drains only go to each self-contained fuel tank compartment. There is a main channel that runs fore and aft with limber holes in the stringers all throughout.

While you're at it, remember that most Posts' lean bow down at rest. This means that any water intrusion or spills from the engine room, (pits don't drain) sinks,water heaters DC or ac fresh water pumps and raw water pumps, all flow to the bow. That's a good place to have at least two serious pumps. One a few inches higher than the other. When underway be sure your high water alarm is working. I would like to have a louder horn but in a rough sea my float switch can fly open and give me a short ring with no water.

I'm intending to replace our several Rule swing-arm float switches -- as they age and fail -- with Ultras, as we did on the previous boat.

The other day I noticed the Rule-Mate pumps, which have some kind of built-in switch... so I asked... and Xylem answered that they use a "field effect sensor to activate the motor."

Don't know what that is... but in our situation, pumps with built-in switches could clear a bit of clutter. More expensive, though.

Also, their largest Rule-Mate is only 2K, so probably not appropriate for a high-water pump. Also, the Rule-Mate installation diagram says to NOT use a check valve on the outflow hose; dunno what that would be.

-Chris

Another vote for Ultra Switches. Trip from NJ to Fl in previous boat found the lazarette completely full of sea water after the gen failed but it never entered the ER. Bertram had some type of step up thing in the keel area. H/W rule alarm switch was bad as well as the same type on the aft pump. Switched to manual and after an hour pumped dry. Strange thing was never found the source and over the next 20 or so years never leaked again. Trashed all the Rule switches and replaced with Ultra. Had a wiring issue with one of them so called the company in S. Fl. Owner answered and was extremely knowledgeable with Bertram's wire colors that differed from the diagram that came with the switches. New to me Bert already has all Ultra Switches. Not cheap but IMO worth the $$. O and make sure of voltage first, as they come in 12 and 24.

Meant to have typed "dunno why that would be."

But mostly I was thinking about potential backflow, as Pascal mentions.

Can't say as I've ever seen a check valves after a bilge pump, but then I also haven't closely inspected that on every boat I've ever been close to...

You've tried the Rule-Mate pumps? What usually fails, the pump, the sensor, or the switch?

-Chris

I have an older 46.
If I drop a hose into the stern hatch and turn it on, the water will run forward to the bow bilge pump.
The stern pump has only ever come on if I had a problem, and the water run aft on acceleration and the bow was high.
The single tube with the plug in my boat is a drain for the area around the fuel tanks.
I believe it is there to contain fuel from entering the bilge if you have a fuel tank leak.
I have never needed to remove a plug to get water to flow from under the back deck towards the bow.
I have had small amounts of oil run from the unplugged tube into the bilge on occasion after I removed the plug..
When I did have water run from the unplugged tube, it was coming from a leaking generator exhaust manifold which was not noticable from the engine room.
Checking the tube is part of my maintenance list now for both water and oil.
If all is perfect in my world, neither water or oil exit the tube

Chris, every Sea Ray I've owned had check valves on the pump outlets from the factory to prevent whatever's left in the hose from draining back.

Pulling those drain plugs is like playing Russian Roulette! I had old fuel, water and sludge seeping out of my front one for a very long time after purchasing this boat but both are dry now.