Noah's Gold by Frank Cottrell Boyce

Being the smallest doesn't stop you having the biggest ideas.

Eleven-year old Noah sneaks along on his big sister's geography field trip. Everything goes wrong! Six kids are marooned on an uninhabited island. Their teacher has vanished.

They're hungry. Their phones don't work and Noah has broken the internet. There's no way of contacting home .

. . Disaster!Until Noah discovers a treasure map and the gang goes in search of gold.