Bilge pumps

I've had my double action bilge pump for many years and it's starting to get "sticky" in its action. My yacht (10' zodiac) is getting older and more probably more "holey" as there always seems to be more water on the floor. Or it could be just me bringing the water on board as I pull crab traps to the pontoon.

I'm looking for a double action hand operated bilge that moves the highest volume of water. Has anyone tested various pumps or know where I can find that data, besides looking up individually.

Thanks,
Nate