You can only use this card name’s (2) effect once per turn.
(1) If there are 2 or more WATER monsters on the field: Target 1 face-up monster your opponent controls; it cannot attack and its effects are negated while it remains face-up.
(2) If a Level 5 or higher WATER monster(s) is Normal/Special Summoned to your field and this card is in your GY: You can Set this card to your field, but banish it if it leaves the field.