When you get to the oil tanks, hit them with your head to destroy the machine guns at the top. Then, go under water and hit your head against the four pillars in the middle and the outside. They should fall and explode. Do this three times for all the oil tanks.

A much easier method (though it will cost health), is to take the torpedoes from the submarine on the bottom of the ocean floor. Hold them in your mouth while charging up your attack. Then, go to the pillar and slam your head into it. Do this three times.

To destroy the tankers without losing health, grab a torpedo near the destroyed submarine. Toss the torpedo at the big tubes that hold the tanker up. Do this to two tubes and you will destroy it. Make sure to destroy the turrets. To do this, bite the yellow orb above the turrets.

After you destroy the oil platforms, do not pick up any more torpedoes from the sunken sub. Instead, swim into the shipyard and find the grate in the water. Destroy it, and swim in. The metal door will open, allowing Jaws into the power generator room. Destroy the two metal tubes sticking up behind the turbine without touching the turbine fan. If you touch it, you will die. Then you must fight the Coast Guard ship. Use the same torpedoes that you used on the oil platforms and Brody will barely escape.

"Taste For Blood" mission: Easy way around most of the mines
When you first enter, move to the far left and head down. Then, stay against the wall and move through. Next, swim to the next blockade of mines and do the same to it, or if you have your swim level maxed out do a charge out of water and go above the mines.