Advanced format ruling
Water Hazard
Card effect (current official text)Once per turn: You can Special Summon 1 Level 4 or lower WATER monster from your hand. You must control no monsters to activate and to resolve this effect.
Current rulings for this card are maintained by Konami.
Rulings data courtesy of Format Library — formatlibrary.com. Spotted an inaccuracy? Flag it in the Advanced forum — sourced change requests get reviewed.