Mega Man X2/Deep-Sea Base

Items

 * Sub Tank (need Leg & Arm Upgrade & Bubble Crab's weapon)
 * Heart (need Leg Upgrade)

Maverick Boss: Bubble Crab
Bubble Crab is one of the weaker bosses you will encounter. He is slow but powerful and he has a bubble shield. He isn't the most maneuverable boss he for the most part crawls across the bottom of the stage. If you are above him he will stop, lower his shield, and jump up into you. Every once in a while he will fire a bubble ring at you so watch it.
 * Weakness: Spin Wheel

He has another attack that will send a series of bubbles to the top of the room. Inside the bubbles are some smaller crabs in them, if you pop them the little crab inside will home in on you and blow up.

So there are a couple of ways to handle Bubble Crab. If you do not have his weakness you can take advantage of his jump attack because he drops his shield and jumps straight up. What you do is either wall jump over him, air-dash, jump, what ever you do just jump over him. As he drops his shield blast him.

On the other hand, if you do have his weakness Spin Wheel. Release the wheels! It will pop his bubble shield and cause major damage to Bubble Crab.