Water Wave

Water Wave (ウォーターウェーブ) is Wave Man's special weapon. When used by Mega Man, it sends a few series of water spouts as a small wave across the floor. It will stop when it hits an enemy that is strong enough to sustain the hit, or until it hits a wall. It can not be activated while Mega Man is in the air. It also negates Star Man's Star Crash

Capacity
In Mega Man 5, one Water Wave uses 2 weapon energy units. With a full weapon energy gauge, Mega Man can use Water Wave 14 times.

Bosses weak against Water Wave

 * Star Man: Mega Man 5
 * Dark Man 1: Mega Man 5
 * Toad Man: Mega Man (Game Gear)

Other media
Mega Man uses Water Wave in episode 13 of the Mega Man animated series.