Water Manipulation – The ability to control water including but not limited to making constructs from water.
Mera (DC) is a deadly combatant with water.
Aquaman (DC) does not have the ability to manipulate water like his wife Mera. In the Silver Age, Aqualad (DC) more or less had the same powers as Aquaman. Later Aqualad became Tempest (DC) and could manipulate water.
In the Young Justice version of Aqualad, his appearance changed and he could make swords out of water among other things.
The Cartoon Network TV series Teen Titans Go!, has a version of Aqualad that looks like the Silver Age version but can manipulate water.
Tsunami (DC) can create tidal waves (DC Who’s Who V1 #24).
Water Wizard aka Aqueduct (Marvel) in Official Handbook of the Marvel Universe V2 #14.
Sea Witch (Marvel) is one of the Young Gods in Spectacular Spider-Man Annual V1 #8.
Aspen Mathews – Aspen Universe – Sourcebook #1 (2016)
Riptide (Image) in Youngblood Battlezone #2.
Water Hazard (Ben 10)
Trading Card Games including many cards dealing with water manipulation.
Aqua 16 Sudden Waterspout
Aqua 29 Sprinkle Water of Tranquility
Aqua 31 Administer Water of Immortality
Aqua 32 Chosen of Water
Conjured Sparkling Water
Water Cannon Brigade
Next 488) Water Mimicry