Drift through life without any real sense of purpose and good things will happen – that seems to be the chilled out mantra of Ben Stassen’s computer-animated adventure with a strong environmental message.

A Turtle’s Tale: Sammy’s Adventures chronicles the 50-year life of the eponymous reptile, from hatching on a beach in 1959 California to his return to the same resort where he shepherds a new generation into the sea with the soothing words, ‘Just put one flipper in front of the other and you’ll be fine’.

Sammy glosses over the swarms of gulls, wheeling overhead, poised to pick off the babies before they reach the safety of the water.

Life can be cruel, though not in Stassen’s film, which ensures that the hero in a half-shell and his aquatic chums escape almost entirely unscathed from an oil spill, pollution and global warming.

The animation is mediocre at best.

Water lapping against a wooden raft doesn’t leave any residue, nor do the turtles’ wet flippers, and when creatures laugh underwater, they jiggle back and forth in the water without generating any bubbles, as if it were thin air.

Finding Nemo created a more richly detailed undersea world, swarming with shimmering life, and that film is eight years old which is a lifetime ago with all of the technological advances to computer animation.

A greenback sea turtle called Sammy (voiced by John Hurt) proudly looks back on his life.

He takes us back to the late 1950s, when the young Sammy (Dominic Cooper) emerged into the world on a Californian beach and struggled to clamber out of the egg chamber.

He discovers the love of his life, the beautiful Shelly (Gemma Arterton), only to lose her to the strong tides.

Drifting on the currents, he meets a leatherback turtle called Ray (Robert Sheehan) and they become best friends.

‘For 10 years, our life consisted mainly of floating and waiting,’ explains Sammy, getting our pulses racing.

As the turtles circumnavigate the globe, they encounter deadly piranhas, a scavenging fish eagle and a Parisian cat called Fluffy (Kayvan Novak), who resents being usurped in his hippy owner’s affections.

A Turtle’s Tale: Sammy’s Adventures is pitched at a very young audience, who will forgive the workmanlike visuals and the comically simplistic lyrics to the songs (‘You can count on me like 1 2 3, I can count on you like 4 3 2.’) Not once are any of the characters in serious peril, and the script paints mankind as both nature’s greatest enemy and its saviour from destruction.

Vocal performances are unremarkable and the lack of gags doesn’t bode well for parents who are press-ganged into taking to the high seas with the flippered, finned and feathered protagonists.

Turtley forgettable.

• Release Date: Friday 25 March 2011
• Certificate: U
• Runtime: 85mins