Episode 1 Dangerous Seas

Chased By Sea Monsters a.k.a. Sea Monsters: A Walking with Dinosaurs Trilogy is about Nigel Marven travelling back in time to visit the seven deadliest prehistoric seas. On his journey he encounters many marine animals, from the predators to the prey. He travels to those time periods on a boat called The Ancient Mariner, a 24 metre long boat with a crew. His means of time travel is never shown but the closest thing to it is his time map, that show the seven deadliest seas and the creatures that live in them. On his dives, he wears a scuba set with a full face mask so that he can narrate while under water. On some of the most dangerous dives, he uses a strong shark cage, which is spherical so that it is difficult for predators to bite it. The series is the second Walking with … programme to star Nigel Marven and was the last Walking with … special to air. It is also the only programme to be narrated by Karen Hayley. Sea Monsters was nominated for Outstanding Visual Effects in a Television Series in the 2004 Visual Effects Society Awards. It also won Best Visual Effects at the 2004 BAFTA Awards. A companion book to the trilogy, Sea Monsters: Prehistoric Predators of the Deep, was published by BBC Books on 16 October 2003. Instead of organising the chapters into the order of the most deadly seas, the book is presented in temporal order. The chapters also feature more creatures than in the television series.
Episode 1 Dangerous Seas – Marks the beginning of Nigel’s quest as he travels back to New York in the Ordovician, 450 million years ago,a world of creepy crawlies and an alien atmosphere, to find the giant orthocone. Nigel, walking through a barren landscape with an oxygen tank containing a special air mix, says that the air during the Ordovician is atrocious and that if he wasn’t prepared with his breathing equipment, he would feel rather sick and would get bad headaches. Due to the presence of high levels of carbon dioxide, plants are not able to grow so no animals live on the land. However, in the water, it was completely different story. About waist deep in the Ordovician waters, Nigel finds a silhouette under the water. It turns out to be a Megalograptus. Later, Nigel finds a large Trilobite corpse on the shore and decides to fit a camera onto the Trilobite. However, in order to do that, he needs to pop out on of its eyeballs. As Nigel fits the camera in, the cameraman turns away in disgust. As the sun sets, Nigel realises that in Ordovician times, the Earth rotates faster and rather than the usual 24 hour long day, an Ordovician day is 21 hours. Nigel and his crew then decide to sleep. The next day, Nigel is in his speedboat. He is equipped with a diving suit which had a special breathing tank attached. Due to the atmosphere, if he dives wearing a normal diving suit, he would become unconscious. He decides to deploy the Trilobite cam into the water. As Nigel returns to the shore, he finds out that the Megalograptus are gathering to reproduce. Nigel quickly makes a run for the shore and tosses some of the sea scorpions away. As he reaches the shore, some of the Megalograptus climb onto his speedboat. The episode then cuts to the Time map and travels forward in time to 230 million years ago, the Middle Triassic in Switzerland. In the Triassic the pterosaurs rule the skies, the dinosaurs have just appeared. However, in the seas, marine reptiles are at the top of the food chain. Nigel sees Cymbospondylus but on his journey. there, he encounters nothosaurs and the creature that defies physics. His last trek of the episode is to the Devonian where he encounters the Dunkleosteus.
Episode 2 Into the Jaws of Death – Starts with Nigel still in the Devonian escaping the wrath of Dunkleosteus. The episode then moves on to 36 million years ago, the Late Eocene in Egypt. The Eocene marks the beginning of the mammal’s success as they begin to dominate the land and the sea, and as Nigel is about to find out, they even rule the bit in between. Nigel encounters a rhino like elephant and the giant Basilosaurus. When palaeontologists discovered its remains, they thought that it was a sea serpent. However, it was later discovered to be an ancient whale. He then examines a photograph of a fossil skull of Basilosaurus and explains the functions of its many different types of teeth. The episode then continues to the Pliocene where he encounters the bizarre Odobenocetops and the titanic shark Megalodon. Nigel shows off the shark camera. He explains that they needs to attach it to the dorsal fin of a Megalodon so that he can record a day of its life. The crew then begins to chuck the chum off of the side of the boat. As Nigel readies himself, the Megalodon erupts from the water and attacks the metal platform.
Episode 3 To Hell… and Back? – This episode starts with Nigel still in the Pliocene still trying to attach a camera to a Megalodon. When the crew of the Ancient Mariner head backwards in time, Nigel says that as the Ice Age begins, the whales that Megalodon preyed on migrated to colder waters, where Megalodon could not follow. Megalodon is doomed to extinction, by hunger. The episode then moves on to the Jurassic where Nigel comes face to face with the giant fish Leedsichthys, the marine croc Metriorhynchus and the giant monster Liopleurodon. The episode concludes in the Cretaceous, Hell’s Aquarium. On the land there’s T. rex, but even the most famous land predator of all time can’t compare to what’s in the water. There, Nigel encounters a plethora of sea monsters and then come face to face with the deadliest sea monster of all. Having done the same thing with present day leatherback turtles, Nigel risks his personal safety to track down the Archelon and ride it. He and the cameraman ride off in the small inflatable raft. A family pod of Tylosaurus attack and completely overturn the raft, plunging the crew into the sea. Fortunately for Nigel, the Tylosaurus seem more interested in the boat than the humans, and they quickly escape back to the Mariner. However that night, as the men sleep, several kinds of mosasaurs appear, apparently attracted to the Mariner, and rush straight to the boat, leaving the crew’s fate unknown!