Released in 2011, Dolphin Tale fictionalised the incredible true story of a bottlenose called Winter, who was snared in a crab trap in Florida and lost her tail.

The plucky mammal was rushed to nearby Clearwater Marine Hospital where dedicated staff rehabilitated Winter by fitting her with a silicon and plastic tail similar to prosthetics worn by human amputees.

The dolphin's remarkable recovery and her subsequent celebrity have ensured a steady stream of visitors to Clearwater, where Winter now shares a tank with another bottlenose called Hope.

Filmmaker Charles Martin Smith, who captained the original film, clearly fell in love with Winter because he writes and directs this uplifting yet wholly unnecessary sequel.

Young audiences will happily wade through pools of sugary sentiment in order to enjoy heart-warming scenes with the dolphins and a stranded sea turtle christened Mavis.

Parents, however, won't find a great deal to buoy their interest besides footage during the end credits of two real-life rescues that inspired Smith's flimsy script.

Several years have passed since Sawyer Nelson (Nathan Gamble) rescued plucky dolphin Winter with the help of Dr Clay Haskett (Harry Connick Jr) and prosthetics expert Dr Cameron McCarthy (Morgan Freeman).

The teenager now works at Clearwater Marine Aquarium (CMA) with Clay's spunky daughter Hazel (Cozi Zuehlsdorff), his grown-up cousin Kyle (Austin Stowell) and trainer Phoebe (Austin Highsmith).

Families flock to CMA to see Winter, which delights aquarium owner Phillip J Hordern (Tom Nowicki), who hopes to expand the site.

Sadly, those plans are put on hold when Winter's companion, an elderly dolphin called Panama, dies and leaves the plucky bottlenose without a pool mate.

Under regulations, Winter cannot be housed alone and a visiting inspector (played by director Smith), tells Clay, "I'm giving you 30 days to correct the problem."

The race begins to find another companion for Winter before Clearwater is forced to give up its beloved dolphin.

Meanwhile, Sawyer realises his feelings for Hazel run deeper than friendship and the lad considers leaving Winter for three months to participate in a prestigious marine biology programme aboard a tall ship.

Dolphin Tale 2 serves no dramatic purpose other than to reignite interest in CMA and its real-life star attraction.

Gamble is a likeable if somewhat bland protagonist and the nascent romance with Zuehlsdorff remains chaste.

Connick Jr flashes his dazzling pearly whites to distract our attention from the hoary dialogue while Freeman makes fleeting appearances as the crotchety prosthetics wizard, who tells one pre-pubescent member of CMA staff, "I've got jars of peanut butter older than you."

Given the product's short shelf life, his character may not survive for a third splash in the dolphin pool.