You have to get a female Masquerain, and a male Pokemon that learns Hydro Pump and is in the Water1 egg group. (Example: Lombre or Swampert) Put both Pokemon in the Day-Care center then, you might find a Surskit egg. If, you do get an egg, then hatch it (by walking for a long time), then you will notice that your Surskit learns Hydro Pump. (By the way, this is the only way Surskit will learn hydro pump.)
Floatzel cannot learn Hydro Pump.
Quagsire cannot learn Hydro Pump.
Azumarill learn Hydro Pump at level 57.
Swampert does not learn Hydro Pump.
Floatzel cannot learn Hydro Pump without the use of hacking.
No, Dragonite cannot learn Hydro Pump.
Floatzel cannot learn Hydro Pump.
Quagsire cannot learn Hydro Pump.
Azumarill learn Hydro Pump at level 57.
At level 40, Kingdra is suposed to learn Hydro Pump.
Swampert does not learn Hydro Pump.
No, Floatzel does not, and cannot learn Hydro Pump without the use of hacking.
Floatzel cannot learn Hydro Pump without the use of hacking.
It learns Hydro Pump at level 48.
blastoise learns hydro pump at 63
Floatzel cannot learn Hydro Pump in any of the Pokémon games as of Generation V.
Well, it's actually Hydro Pump, but Jellicent can learn it at level 53.