FINDING DORY (U) 103 mins. Featuring the voices of Ellen DeGeneres, Albert Brooks, Ed O'Neill, Kaitlin Olson and Hayden Rolence.

HOW can you remember you have a family if you have short-term memory loss?

That question is the wind beneath the water wings of Pixar's joyous computer-animated sequel, which revisits the colourful characters 13 years after worrywart clownfish Marlin (voiced by Albert Brooks) was reunited with his beloved son, Nemo.

Their forgetful pal, Dory (Ellen DeGeneres), the uproarious comic relief of the first film, is promoted to head of the school for directors Andrew Stanton and Angus MacLane's journey of self-fishcovery that once again abandons the safety of the reef for perilous waters.

In almost every aspect, Finding Dory is the emotional and comical equal of its predecessor, dazzling the senses with stunningly realistic visuals and Thomas Newman's buoyant orchestral score.

The script effortlessly tugs heartstrings in between cute verbal and sight gags, including a running joke about the voice of an A-list Hollywood actress, whose dulcet tones become a shimmering beacon of hope in the film's darkest moments.

An adorable animated short entitled Piper precedes and complements the main feature, chronicling the fortunes of a sandpiper hatchling as it learns to forage for food at the water's edge.

Tissues at the ready...

Dory is the next-shell neighbour of Marlin and his young son, Nemo (Hayden Rolence) on the Great Barrier Reef.

During a field trip to witness the stingray migration, the loveable blue tang experiences a rush of fragmented memories of her parents Charlie (Eugene Levy) and Jenny (Diane Keaton).

"I miss 'em", Dory tells Marlin and the plucky fish embark on an epic quest to California to reunite the forgetful daughter with her loved ones.

Initially, the travellers ride strong currents with sea turtle Crush (Andrew Stanton) and his bodacious brethren, but when they eventually arrive at the Marine Life Institute, Dory is separated from her pals.

She languishes in quarantine with a grouchy septopus called Hank (Ed O'Neill), who possesses remarkable powers of camouflage.

Meanwhile, Marlin and Nemo abide by Dory's mantra - "Just keeping swimming" - and enlist help from wise-cracking sea lions Fluke (Idris Elba) and Rudder (Dominic West), near-sighted whale shark Destiny (Kaitlin Olson) and a beluga whale called Bailey (Ty Burrell), who has lost his echo location as the result of a concussion.

"I hit my head very hard. Do you see how swollen it is?" laments Bailey.

"Your head is supposed to be big," retorts Destiny, "You're a beluga!"

Finding Dory mines the central character's one-joke disability for gentle laughs without meanness or obviously treading water.

Set pieces including a frenetic chase involving a fearsome predator of the sea are nimbly executed and the introduction of O'Neill's cranky cephalopod is a master stroke.

DeGeneres' vocal performance exudes warmth and innocence, compelling us to root for her through a couple of the film's outlandish narrative detours.