Originally published by Allen & Unwin Australia, 2016, as Escape to the Moon Islands.
Summary
"Forty years after a devastating flood changed the face of the earth, new consequences and challenges are still surfacing. Twins Will and Annalie thought the hardest part about this year was going to be their separation when bookish Annalie began life at a prestigious Admiralty-run boarding school and avid sailor Will stayed behind in the flood-damaged slums. But that was before ... their father disappeared, leaving a single coded clue to his destination. Desperate to find their father, the twins set out in the family's small sailboat"--Publisher marketing.