Can computer case fans be powered by batteries?

I have a couple left over case fans and they say they are DC so I was going to use them in a little project I'm making. Are the volts and amps listed the required to power it... also which type will work underwater.. I can remember if it's the magnetic type or what not...Can computer case fans be powered by batteries?
Most computer fans are 12 VDC. The voltage and current should be listed on the fan someplace. I don't think they'll work underwater. They're designed to move air and won't have the power to push the much heavier water. They should run for a bit under fresh water. I don't know how long they'd last in salt water. The best thing to do might be to get a small battery operated pump. Remove the pump part, being careful not to hurt the seal of the motor, and connect the fan blade to the shaft of the pump motor. Or maybe the pump itself can do the job you want the fan to do.