Marine, known in the original Japanese version as Marine Boy, is the teenage protagonist of the anime series. He is a highly skilled young adventurer who serves as a primary agent for the Ocean Patrol, an international organization dedicated to protecting the world's oceans and maintaining peace beneath the waves. He is presented as a capable and courageous individual, possessing impressive physical abilities honed through extensive training. He is an exceptional swimmer and diver, and his martial arts proficiency allows him to handle both human and aquatic antagonists in direct combat. His personality is marked by strong intelligence, determination, and a headstrong nature that drives him to take decisive action in the face of danger. His primary motivation is a deep-seated sense of duty and justice, compelling him to defend marine life and human interests from a wide array of threats, which include undersea pirates, rogue scientists, monstrous sea creatures, and environmentally destructive schemes. This motivation is deeply personal, as his father, Dr. Mariner, is the chief scientist of the Ocean Patrol and the designer of many of Marine's specialized tools. Marine's role in the story is that of the central hero, routinely embarking on missions from the patrol craft P-1 alongside his two crewmates, the lean Piper and the stout Bulton. He is the epitome of a dedicated field operative, often taking the most dangerous assignments personally. His key relationships are foundational to his character. Doctor Mariner serves as a father figure, mentor, and the technical authority who provides Marine with his equipment and mission briefings. His most trusted companion is Splasher, a highly intelligent white dolphin who can be summoned by a whistle built into Marine's ring. Splasher is integral to many rescue and combat sequences, acting as a swift and reliable partner in the ocean depths. Marine also works closely with the eccentric inventor Professor Fumble, whose creations often assist but sometimes complicate their missions. He is aided by friendly underwater allies such as Neptina, a young mermaid who possesses a magical pearl with prophetic abilities, and Clicli, a cheerful and inquisitive boy from an ancient underwater kingdom. Marine's development is conveyed through his accumulation of experience, where each solved crisis reinforces his commitment and hones his skills. As the series is structured around self-contained adventures, his growth is less about a changing personality and more about the deepening of his competence and wisdom as he repeatedly overcomes new and varied challenges for the greater good. His notable abilities are heavily augmented by advanced technology. He uses oxy-gum, a special chewing gum that allows him to breathe underwater for extended periods. His red wetsuit is made of a durable, temperature-resistant material that protects him during hazardous missions. His boots contain propeller packs and retractable flippers, granting him remarkable speed and maneuverability in the water. His primary weapon is a folding alloy boomerang capable of cutting through metal and deflecting bullets. He also wears a helmet equipped with a radio for communication. All of these tools, combined with his natural athleticism and bravery, make him a formidable and effective defender of the seas.