An unprecedented great white shark expedition begins. A brazen team of seasoned fishermen and an innovative scientist join forces to unlock the mysteries of the world’s largest predatory fish.ish.

With just a few days and 3 tags left, the great white expedition team amps up to tag their next sharks. But bait is running low and tensions high. A big biter takes the line and battles for over an hour. And then they come across a fresh seal kill with a big shark dining on it. Can they lure the great white onto their line and onto the boat?

The expedition to the Mexican island of Guadalupe is on its last day. Throughout the past week, the great white team set new records for landing, tagging and safely releasing the biggest sharks ever! But on this final day, the best is yet to come. Until now, the most prized treasure to help solve a puzzling mystery in the great white story has been elusive. With only a few hours left they finally get what they need -a blood sample from a mature great white female.

With 11 sharks successfully caught, tagged and released, its time for Dr. Domeier to put his technology to the test. The expedition team embarks on its longest and most dangerous voyage yet, more than a thousand miles into the Pacific Ocean, to find their old friends. As they leave the marina, some of their sharks are already pinging in, luring them offshore. Weather, mechanical failures and fatigue are just a few of the obstacles looming ahead, but the rewards could be immense and include groundbreaking discoveries on this apex predator of the sea.

The crew continues their expedition deep into the SOFA, the shared offshore foraging area, and the stakes in determining how great whites survive here are high. So far, they've lost more than a third of their bait and they haven't come close to catching a great white - yet. In their quest to land a big one, they discover two species of squid, which "the Doc" theorizes must be a good part of the sharks' diets.

The crew is on the verge of a scientific discovery that could finally solve the mystery of where great whites breed. To get the proof he needs, Dr. Domeier sets off to Guadalupe, Mexico to collect sperm samples from wild great whites! When they locate a large male, they immediately jump into action in an effort to prove Dr. Domeier's theory.

The adventure continues at Guadalupe Island, Mexico, where Dr. Domeier is on the verge of proving great whites come here to breed. But with his first sperm sample ending up inconclusive, Domeier desperately needs the fishermen to land another on the cradle. The sharks are feisty, the stakes high, and the team ready to catch another giant male.

An unprecedented great white shark expedition begins. A brazen team of seasoned fishermen and an innovative scientist join forces to unlock the mysteries of the worlds largest predatory fish. They seek to catch adult great whites, bring them on board their vessel, take DNA and blood samples and attach the most sophisticated tracking devices before setting them free. What it takes to make their first catch challenges their skills and preconceptions.

After the success of catching and releasing their first great whites, the team sets its sights on catching a bigger shark - a female. But a couple of feisty males require some on-board redesigns and deliver a scientific surprise. And then comes Curly.

The great white shark team returns to Guadalupe Island with new information, new crew and renewed scientific ambition. Re-tooled tags, a blood sampling kit and actor Paul Walker join the mission to save the sharks. We discover what has happened to the 4 sharks tagged the previous year and catch and release two more including the biggest girl yet - 16 1/2 foot (5 m) Kimel.

The Shark Men head to the rocky, barren Farallon Islands off the coast of San Francisco. The National Marine Sanctuary, which oversees all activity in the area, has granted the Shark Men the first-ever permit to hook a great white shark at the Farallones for research, with the caveat that a sanctuary observer be onboard. Their first catch does not go smoothly, and the crew must eventually release the shark with part of the hook still caught in its throat.

After their permit to fish off the Farallon Islands is suspended, the Shark Men anxiously wait to hear whether they can resume their expedition in the closely protected marine sanctuary. While expedition leader Chris Fischer and Dr. Michael Domeier plead their case for reinstatement before the National Marine Sanctuary officials, the crew members use this downtime to modify their equipment and lessen the potential danger to any shark caught in the future.

The Shark Men head to Southern California just off the shores of Malibu, and find the waters teeming with juvenile great white sharks just 300 meters from where beachgoers surf and swim unknowingly close by. Juvenile sharks are of keen interest to the Shark Men, who want to learn more about the younger years of the fish's life cycle to help them better understand the whole story of the species.

As their expedition off the coast of Malibu, California, continues, the Shark Men suspect that juvenile great whites are using the area as a kind of nursery, with its warmer and shallower waters providing the young sharks with a perfect place to grow and prepare for adulthood. The crew wants to catch more females since they have different migration patterns from the males and are the key to locating and eventually protecting shark birthing sites.

The Shark Men are headed back to the waters where they have successfully caught and tagged almost a dozen sharks; Guadalupe Island. Dr. Domeier almost has enough data to support his theory about great whites mating at the island. But still needs a few more blood samples, his primary target; adult females. No matter how familiar the waters are nothing goes off without a hitch for this team.

The Shark Men have reached their last days at Guadalupe Island, and want to make the most of it. They catch one more female great white, Annika, and Dr. Domeier hopes that a blood sample from her will complete his Guadalupe breeding ground research. They also wrangle Apache, a male, a fighter, and their biggest shark to date.

The Shark Men are once again in unfamiliar territory; the Sea of Cortez. This time they have a different agenda; they are chasing Amy. Dr. Domeier believes Amy has come to the Sea of Cortez to give birth. The crew soon finds out that this phenomenal region has much more to teach them. They will go on a journey to find the truth behind the great white shark folklore surrounding this area. As the crew uncovers secrets of the Sea of Cortez; the search for Amy continues.

The Shark Men continue the search for a great white named Amy who they believe is about to give birth. The team will search by air and sea, hoping for the biggest accomplishment of their entire scientific mission. The Sea of Cortez seems to be a perfect habitat for a great white shark nursery, though it's full of man-made dangers. It is a high-traffic area for use of long lines and gill nets, and though sharks aren't the target, they often get caught in the crossfire.

This time the Shark Men aren't searching for sharks they're tracking the giant Humboldt squid. Little is known about the elusive monster that can grow as long as a school bus. Joined by three squid experts, the Shark Men scour the Sea of Cortez by spotter plane and boat in the hopes of finding a giant squid. After days of finding only a juvenile Humboldt, Captain Brett manages to catch a fully mature Humboldtbut what the cameras catch is even more spectacular.

The Shark Men are in the beautiful, plentiful Sea of Cortez continuing their search for Architeuthis- the giant squid. The crew is joined on this expedition with a world famous giant squid expert to hopefully be the first ones to capture footage of this elusive animal in its natural habitat. The team already knows the creature of the deep could call the Sea of Cortez home, but the question they want answered is does it? The two teams will work together to find that answer from diving with sperm whales to studying the Diablo Rojo or Humboldt squid.

The crew are joined by a fresh science team and face new challenges as they track tiger sharks in the Revillagigedo Islands.

The hunt for hammerheads continues off Socorro Island, and Dr Pete Klimley hopes to uncover the mysteries of shark migratory behaviour.

The Shark Men are challenged as never before. They hook two giant tiger sharks, but their sheer power catches them off guard.

After a long period of frustration, modified tackle brings the crew success. Two female tiger sharks, Sharon and Lizzie, are added to the tally.

As the long, gruelling mission starts to wind down, the tally of tagged sharks continues to rise – along with tensions between the team.

Expedition leader Chris Fischer pushes the team to the limit as they seek one more tiger shark and three more silvertips before leaving the area.

The team battles shark-finning poachers as they attempt to tag hammerheads in the waters surrounding the Cocos Islands.

When Todd hooks a giant tiger shark and the divers abandon a scientist in dangerous waters, it leads to a growing divide over safety issues.

The team finally adds hammerheads to their list of tagged sharks, but the relentless pace of work is wearing some of the men down.

In the last days of the expedition, the team tries everything from midnight fishing to swimming with sharks to tag the elusive hammerheads.