If you're looking for manga similar to Koukai Ouji no Yuuga na Funatabi, you might like these titles.
One of the surveillance ships of the company Ferret went missing for some time. Once the ship was found, all 115 members aboard the ship were completely missing. No trace of their existence was found aboard the ship. Masato's sister works for Ferret, and he was tasked to bring her supplies for the upcoming work to investigate this mysterious ship that returned without her crew. He meets a beautiful girl named Uto at the company, who also had a brother that worked for Ferret and went missing inside the ship. Now Masato and Uto must embark on a mission to discover the mysteries of the unknown island where the missing crew has been left.
The once-sunken Battleship Yamato returns from its watery grave to wreak havoc across Japan.
Cruise is the story of Yamada Kohei, a doctor who gives up a landlubber medical career to serve as a ship's physician, and the people he meets on board Japan's largest luxury liner, the Phoenix. He rejects a university colleague's insistence that he turn to teaching instead, preferring to stay and learn about life as it happens from the ship's passengers.
A story about the hardships of the crew of a crab fishing ship as they struggle under capitalist exploitation.
In the year 20XX, the state of world affairs is changing at a dizzying pace. This is particularly clear in the growing military strength of countries neighbouring Japan, the issue of resources on the sea floor, disaster relief, underwater transport, maintaining order on the high seas and island defence. In response to a near-skirmish with China over the much-disputed Senkaku Islands, Japan builds the aircraft carrier "Ibuki" and organises a new fleet...
Year 20YX. Global warming is causing sea ice to decrease in the Arctic Ocean. The Maritime Self-Defense Force destroyer Shiranui, on which Kaburaki, a candidate to become the next captain of the Ibuki, is dispatched to conduct research. Suddenly, a civilian research vessel is attacked by someone...! The "Shiranui" quickly uses its weapons to protect the civilian ship, but...! Who attacked it? What was the reason for the attack!