Adjective : a submersible pump.    From Dictionary.com. 

Note the approximately 20 foot (7 meter) limit in height the pump can be located above the water level for the non-submersible pump.    From Wordnik.com.  [Chapter 14] Reference

In a non-submersible double-insulated motor design, the largest motor I have ever seen is 825W, a little over 1HP, but that was not for a pump, it was for a tool.    From Wordnik.com. Reference