Personally, I see little point in having a bilge pump on a O/B rib as there is no bilge, only a sealed floor. Unless you have a deep well to protect it, they just get booted constantly and then, it's only emptying the well.
Ribs are designed to be wet and a have a darn great 'drain' hole back aft.
The only time that I ever used one was to clear a bit of rain water if she'd been left on the water overnight. I never wear footwear that wont cope with an inch of fresh water.
It's an 'I must have a bilge pump' item, nah you don't.
I/B ribs are a different story.