The water temperature varies according to the route you choose. In general, the water temperatures are as follows:
Komodo North – 27-30 degrees Celsius
Komodo South – 21-27 degrees Celsius
Raja Ampat – 27-30 degrees Celsius
Maumere – 27-30 degrees Celsius
Alor – 21-28 degrees Celsius
Banda Sea/Ring of Fire/Forgotten Islands – 27-30 degrees Celsius
Lembeh – 25-29 degrees Celsius
Halmahera – 27-30 degrees Celsius
Please note this is just a guideline and water temperatures can vary.