text: Photographer Seth Casteel's unique pictures of dogs swimming underwater managed to captivate an international audience, but now he has a new subject: babies. Casteel has found a remarkable new way to capture images of toddlers at their most playful and pure as they dive down into the deep during their first swimming lesson. The pictures for his new book, Underwater Babies, reveal adorable babies as they explore the underwater world, chubby-cheeked, curious, mischievous, and playful, all captured in his up-close-and-personal signature style. Scroll down for video . Super swimmer: Zoe Ubiera is five-months old and was one of 750 babies that Seth Casteel photographed . Caped crusader: The babies also added their own flair with this one dressed in a cape and mask . Unsinkable: Seven-month-old Zelda calmly paddles along as Seth Casteel snaps away . Oceanic: Nine-month-old Khyleigh takes like a duck to water as she swims towards the camera . His pictures are innovative and take on an air of excitement as the youngsters swim beneath the waves. Casteel says he was drawn to create his new book, Underwater Babies after hearing of the shocking statistics of the numbers of children that drown. Kids between one and four have the highest rates of drowning than any group in the nation. 'The book is a celebration of babies, but there's definitely a serious element to it,' Casteel told Today.com. 'A big reason I wanted to make this book is to promote the cause of water safety for babies. I just want to let people know about the benefits of these classes and that they are something to strongly consider.' He created the book by heading along to water safety classes for babies at swimming pools in ten different states. He photographed around 750 babies in schools across each of the states to create Underwater Babies, which will be released on April 7. Acquatic: Michael, 12 months, explores underwater with his goggles on . Playful: Valentina, nine months, takes a dip underwater with her rattle . Under the sea: A seven-month-old named Ayla takes the plunge in a mermaid costume  in photographer Seth Casteel's new book, Underwater Babies . Serene: Casteel hopes to use the adorable photos of babies like 4 1/2 month old Michael to promote water safety for toddlers . 'I only had a limited window to really seize that moment in time because they can only go underwater just for a moment,' Casteel said. 'I could only take four or five pictures really quickly. Maybe the baby turned or there were bubbles or the instructor got in the way. I was never frustrated because that's the nature of it. You get what you get.' Apart from promoting his new 70-page book containing his creative pictures, Casteel said that he was eager to get the message across about water safety. He was spurred along after hearing a story about an 18-month old baby who drowned in a pool at a family reunion where over 40 people were present, yet the baby died after being left unattended. Floater: This 11-month-old named Warren is happy in the few moments he has beneath the pool's surface . Snapshot: Casteel often only had a second or two to capture the images of babies like Emerson who is 7 months old when they briefly went underwater . The babies in the pictures are being taught to 'self-rescue,' in which babies are taught to hold their breath underwater, kick their feet, turn over to float on their backs and rest until help arrives. The technique was pioneered in the late '60s by Harvey Barnett, who at 18 became determined to teach infants to swim after the drowning of a neighbor's child. His methods have spread around the world and are now taught in numerous clinics and imitated widely. Underwater Babies by Seth Casteel is published by Headline on 7th April at £11.99. Diver: Casteel shot photos of more than 750 babies across ten states including this 11-month old named Colton . Super scuba: Claire is seven-months old but she appears calm as she swims silently .
target: Seth Casteel traveled across ten states and took more than 750 children for his new book, Underwater Babies .
  He is hoping his photographs will encourage parents to teach their children to swim from an early age .