The Great Wave of Tamarind — Nadia Aguiar

Penny Nelson grew up listening to her older sister and brother recount their adventures in Tamarind, a magical island not found on any map, but she sometimes she can't tell which of her memories are hers and which are theirs.

After drifting out to sea, Penny once again finds herself on the shores of Tamarind. But things are wrong on the island: portals lead to treacherous places, a strange creature is wreaking havoc, and a Great Wave is coming to bring the Bloom, magic that can stabilize the island. Whoever completes three challenges gets to catch the Bloom―and keep some of that life-changing magic for their own use.

To save Tamarind and collect the magic, Penny has to brave dark ocean depths, survive the perils of the jungle, and outwit a cunning creature bent on bringing chaos.