The Birth: When a ship's laborer; Morrie Bench was knocked into the sea while the crew was testing a new under-water generator, a bizarre set of circumstances (failure of the generator and presence of volcanic gasses and the rest of the hoopla etc. etc.) changed him into Hydro-Man. This was seen in the Amazing Spider-Man #212.

The Alter Ego: Morrie Bench, having no better alternative took up a job as a laborer with a shipping company. He had to be a bit demented to blame Spider-Man for his accident that gave him super powers.
Single, he has been trying to get the attention of a lady by the name of Sadie.

The Legend: Once transformed, he discovered the nature of his powers slowly. Because of his slightly crazy and aggressive temperment, Morrie considered his power as a curse and readly blamed Spider-Man for the accident just because the web slinger was present on the ship with him.
Naturally, he went on a revenge seeking mission and finally confronted Spidey. But the battle was a total washout as Spidry quickly got accustomed to his new enemy and defeated him.
Hydro-Man has teamed up with Sandman on a few occasions, but that was before Sandy was reformed.
Hydr-Man's powers include being able to change his mass into water and can traverse with great speed through waterbodies and pipes. He is capable of manipulating other water bodies. Hydro-Man can also propel forceful water jets from himself as well as propel his entire watery mass with great force on his victims. The only hitch is that he can expend his energy and dry up if he does not replenish his watery form.

Amazing Spider-Man #212