Monster Odyssey. The Eye of Neptune

Prince Dakkar, son of an Indian rajah, has issues with authority. Expelled from the world's finest schools, he is sent to an unconventional educator, Count Oginski. Dakkar plans his escape immediately. But something about the Count intrigues him, including a top-secret project which he shares with Dakkar - a submarine. But others are interested in the Count's invention and what it might achieve and, when masked men kidnap the Count, leaving Dakkar for dead, he doesn't know who was responsible. It could have been British Intelligence, or perhaps a sinister figure known only as Cryptos. Either way, Dakkar is determined to rescue the Count. Taking the prototype submarine, he sets off for adventure.
Cue shark attack, giant sea creatures, spies and an evil megalomaniac. From his undersea refuge, Dakkar plans to take them all on . . . with a bit of help from a Girl.