I understood recently that a wet/dry pump (a "shop vac", that is, though not necessarily from that brand) functions by creating a vacuum in an air-tight chamber. The vacuum sucks in anything near the hose, whether it's wet or dry.
I've also seen one manufacturer advertise that some of the wet/dry vacs in their product line can function as a wet pump (in addition to being a wet/dry pump).
I like the idea of using one tool for both functions (in terms of both storage space economy and pocket economy). I'd be using the wet/dry vac to clean the garage floor (maybe 4-6 times a year) and the wet pump function to empty the water on top of a pool cover (somewhere from 250 to 500 gallons, once or twice a year).
Is it indeed the case that a wet/dry vac that can double as a wet pump is capable of continuously pumping? Any wet/dry vac can be used as a 2-stage wet pump (fill, empty, repeat), but doing that 25-100 times in a row is not amusing. Did I understand correctly and some wet/dry pumps can indeed continuously pump water?
I would be perfectly fine with a device that sucks water from the hose, but then allows that water to drain via a syphon from a garden hose, just so long as this process does not need user intervention until it's done.