"Predator In The Bay" mission - 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.

Unlimited health - Collect all 50 hidden treasure chests outside of story mode at the Open Ocean West, Open Ocean South, Open Ocean East, Grand Occasus Canals, Underwater Caves, and Fisherman's Isle. Save the game. When that saved game is resumed you will have unlimited health.

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.

Launching objects - Try to grab mines, barrels, and buoys and launch them at your target.

Ability points - As soon as you get ability points, use them on Health first, then on Speed, Power, Accuracy, and finally Hunger in order. This order lets you get the best attacks and helps complete the free missions easier.

Attacking swimmers - When attacking a large number of swimmers trying to escape, attack them stealthily and drag them farther out so you have more time, then eat them.

Body Bomb - To do the Body Bomb, hold [L] to charge , then jump out of the water when near a boat. Release the [Left Analog-stick] and Jaws will jump out of the water and land on a boat and sink it.

Easy points - An easy way to get fast points is to go to the open ocean south. Then, go as far south as possible. Start attacking boats until police boats begin arriving. Attack them to rack up points. Using the Corkscrew attack is recommended, as it deals massive damage and almost certainly sinks the boat. Sinking the boats results in 1,000 points. Blowing the boat results in 2,000 points.

If you grab a human, pull them deep underwater, let them go, then swim in circles around them, you will start to scare them as they resurface. Once they are at the surface, swim up onto them gently to lift them out of the water. You will scare them to death. This does not seem to kill humans that are on the surface already.

Jumping up on beach - Grab someone with [Black] and go far back. Go towards the beach. When you are about to hit, press [R]. You will fly up on the beach, sometimes very far. Note: You must have special ability. Also, you must get back in water within ten seconds or you will die.

Sinking boats - A fun way to sink a boat is to get someone in the water. Then, hold [Black] to grab onto them. Next, swim towards the side of the boat and press [R]. Note: You must have the special ability. This works best on small boats, but sometimes works on medium size boats if you have precise timing.