Man
Carp - He can swim faster than any sea creature.

Woman
Sonar - She can send sonar frequencies to communicate with any type of seas creature/mammal.

Boy
Shark Fin - possesses blades of energy that are placed near his forearms and back. These blades are used as defence mechanism and for transportation.

Girl
Abyssia - can create gravity fields; come in handy in battle and travelling into deep parts of the ocean.