Written by Lucy Daniels.
I have read about four of the Dolphin Diaries series, plus loads of her Animal Ark series. Most of them are good, some are average.
Jody McGrath is home-educated on her boat that her parents own, the Dolphin Dreamer. She sails all around the world researching all kinds of whales and dolphins, from the usual bottlenose dolphin to the massive killer and pilot whales. My current book, Following the Rainbow, has reached a sad bit where a pilot whale is badly injured.
These series are definitely for people who are looking for a light or short read and are interested in whales and dolphins.