Zoologist Nigel Marven is taking BBC viewers by the hand and leading them back in time again - to an ancient world of spectacular aquatic beasts.
By Julianna Kettlewell
BBC News Online
Sea Monsters, which follows in the foot-steps of the Giant Claw and in The Land of Giants, focuses on seven geological periods between 450 and 4 million years ago.
The series aims to enlighten viewers as they accompany Marven on his "perilous" hunt for the most lethal sea monster that ever lived.
But some scientists fear it sacrifices accuracy in the name of high drama - a criticism that has been thrown at the BBC in the past for its other big-budget prehistoric "natural history" programmes, such as Walking With Dinosaurs.
Sea Monsters is a fast moving extravaganza of big teeth and snapping jaws.
An ongoing theme is Nigel Marven's thrashing cattle prod, as he apprehends a giant squid or armoured fish. Often this is accompanied by a little squirt of watery blood, in case you have missed the point.
It is fun, unapologetic entertainment. Sea Monsters cost £3m to make, and it intends to be enjoyed by all the family. But woven into the action are some serious facts.
The programme-makers want to show us a magical by-gone world, and teach us something about the weird and magnificent animals that lived there.
"We build up a picture about the animals from as many sources as possible," said Jasper James, the executive producer.
"We talked to palaeontologists and zoologists so that we could be as accurate as we possibly could. We didn't say anything unless there was some evidence for it."
Giant sea scorpion
In the first programme, Marven's ankles are accosted by a giant sea scorpion, or eurypterid, which lived 450 million years ago in the Ordovician Period.
The Ordovician was characterised by barren lands and low oxygen levels, since vegetation was still scarce.
Eurypterids were the metre-long ancestors to modern scorpions.
They possessed the equipment to breathe in water and on land, and were one of the first amphibious animals.
Nigel Marven lands his boat on an Ordovician beach that is positively swarming with sea scorpions. He tussles with them and they puncture his dingy.
"They would congregate en masse on the beaches to mate and moult," said Dr Simon Braddy, a palaeontologist from Bristol University.
"Sometimes during this mass congregation, they would eat one another - cannibalism has been recorded."
Dr Braddy, who is an expert in giant sea scorpions, is satisfied that Sea Monsters portrayed the creatures as accurately as possible.
"They sent me several e-mails so I could comment on the way they had made the eurypterids," he told BBC News Online. "Their first model was not very good at all, but in the end I think they had got it just right."
Not David Attenborough
Sea Monsters represents another move away from the traditional "David Attenborough format" of documentary. It aims to inform, but it also tries to take the audience on a white-knuckle ride.
As a viewer, you might feel like a child in front of a theatrically over-the-top pantomime.
"We don't think it is patronising," said Jasper James. "If you can enjoy the drama of a programme while learning something then that's great."
But Richard Dawkins, the Professor for the Public Understanding of Science, is not impressed.
"I think the Nigel Marven programmes are awful, awful - really naff," he said.
"It is as though they think the public are so stupid they can't enjoy the spectacle of the animals themselves.
"Perhaps the phrase 'dumbing down' has been done to death. But isn't it at least patronising and condescending when television people assume, without asking them, that their audiences can't cope with science unless the pill is coated with the sugar of personal anecdote?"
Professor Dawkin's more serious criticism focuses on the blur between what is known and what is just speculation.
For example, the mating behaviour and breeding habits of prehistoric animals can only be guess work - but this is not made entirely clear.
He said: "In Nigel Marven's past programmes they didn't give the viewer any indication of what is known and what is conjecture."
The first episode of Sea Monsters was screened on BBC One at 1900 GMT on Sunday 9 November.