The Mega Mech Shark is fought in three phases. In the first part Mega Man confronts the tail, which releases homing missiles. The second part is the body, which has spikes on it and has two hatches that release small enemies. The last part is its head, which releases several lasers from its mouth.
The tail rises up and down, firing homing missiles. Fortunately, they can be demolished easily by the Mega Buster/Proto Buster. When the tail is lower, use the Laser Trident to pierce through the missiles to attack the main gun, which takes damage only when it's opened. However, if the tail is higher, use Hornet Chaser to cause moderate damage to the missile launcher.
The next phase is quite simple if you have any energy for the Tornado Blow. It will blow all the torpedo enemies upwards and damage the hatches. If the Tornado Blow is depleted, use the Magma Bazooka to diagonally blast the hatches and avoid the spikes.
The last part's weakness is the laser mouth, which only opens when firing. The best weapon against the mouth is the Hornet Chaser, which will chase the laser even when closed. If it runs out, it's best to use the Laser Trident. The Black Hole Bomb can also be used, as it absorbs the lasers.
- This boss is, to a certain extent, similar to the U-555 sub-boss in Tidal Whale's stage in Mega Man X5.