While a little slow, standard inexpensive submersible pumps that plug in and you attach a hose to are like tape measures, flashlights, duct tape, and coffee.
They should come standard with every home.
The uses for these little gems are endless...not the least of which is to pump water off a pool cover, rig up a makeshift aeration fountain to raise PH without raising TA, empty a spa (because the drain plug is aimed at my foundation!!!!), pump out water from where it shouldn't be such as a basement or crawlspace (if one should use my drain plug on the spa instead of the pump), and to loan to your friends who haven't seen their benefit yet...
Of every purchase my dad ever suggested I make, that little pump is my favorite. And having it really puts me in the running for smartest mom in front of my girl friends.