Well, it depends on the specific story. Some 'phantom submarine' tales might be based on real submarines that were involved in covert operations. For example, during the Cold War, both sides had submarines doing secretive patrols and surveillance. If one side detected an enemy sub briefly and then lost track of it, it could be called a 'phantom submarine'. So in the context of a true story, it might be a real military sub.
Since I don't know the exact 'submarine kid story', it could be the kid as the main character. Maybe there's also a mentor figure, like an old sailor who teaches the kid about submarines.
A really cool submarine book is 'Voyage to the Bottom of the Sea' by Irwin Allen. It has a lot of exciting adventures and scientific exploration as the crew of the submarine Seaview faces various threats and mysteries. It combines action, science, and adventure very well.
Create relationships between the characters. Maybe there are two crew members who have a love - hate relationship. As the story progresses, this relationship can evolve. They could start off arguing but then come to rely on each other during a crisis in the Titan submarine, which would show growth and development in both characters.
The main characters in the 'yellow submarine graphic novel' could be a diverse group. There could be a brave and curious explorer who leads the way in the submarine. There might be a mechanic - type character who keeps the yellow submarine running smoothly during all the adventures. And perhaps there are some friendly sea creatures that team up with the submarine crew, like a wise old turtle or a playful dolphin, all of them together forming the main cast of characters in this graphic novel.
The main characters in the 'beatles yellow submarine graphic novel' are, of course, the Beatles themselves: John, Paul, George, and Ringo. They are on the adventure in the Yellow Submarine, facing various challenges and having encounters in the strange and wonderful world of the story.
The main characters are, of course, The Beatles themselves - John, Paul, George, and Ringo. They are on a journey in the yellow submarine. There are also all those wacky and colorful characters from the original Yellow Submarine story like the Blue Meanies.
It could be a lost or abandoned submarine. Maybe it was part of a military experiment that went wrong, and it's now drifting around, appearing and disappearing like a phantom.
" I Have a Water World, Fishing a Nuclear Submarine " was a completed novel by Ji Yu. This novel told the story of the protagonist owning a water world and obtaining various rewards by salvaging wreckage such as submarines. Other than that, there were other similar novels, such as Survival in the Deep Sea: The First Submarine and Treasure Hunt in the Ocean: The First Fighter.