It is an adaptation from Watson's best-selling memoir of the same name. The sailor will consult on the production.
The movie will be filmed in Queensland and Sydney later this year, and is written and directed by Sarah Spillane (Around the Block, This Life).
Oscar-nominee Josh Lawson (Mortal Combat, Bombshell), has also been cast in the film.
Paquin rose to fame in 1993 when she made her acting debut in Jane Campion's The Piano. She became the second-youngest Oscar-winner in history for her role in the film as Flora McGrath.
She has had several high profile roles since, including Sookie Stackhouse in HBO's True Blood, and she currently stars on the series Flack which she also executive produces. She has also played roles in movies X Men: Days of Future
Curtis also stared in The Piano as Mana, plus 2002's The Whale Rider. His most recent roles include Jonah in 2019's Fast & Furious: Hobbs & Shaw, and he is playing Tonowari in the Avatar sequels.