We'll start with the "Odyssey" part. An odyssey is a long journey full of adventures from which one derives knowledge or wisdom. The word and its meaning come from Homer's Odyssey, that piece of classical Greek literature about an ill-fated sea voyage.
It's axiomatic for odysseys that things not go as expected. If everything had happened as Marco had hoped, we wouldn't have much of a story. Nor would Marco (and we, the readers) have learned anything from the experience. What's more, the adventure sure wouldn't have been as funny, if at all. Thus, throughout Marco's journey, everything that can go wrong often does.
The "Gullwing" part is a bit harder to explain. Marco's surname is unorthodox for his ancestry, but it's entirely fitting. His surname is meant to evoke seagulls. Seagulls are coastal birds, keeping with the book's nautical theme. They are capable of soaring for large distances at a time. By comparison, Marco's travels involve long stints of ocean voyages to far-flung locales.
Moreover, seagulls are particularly good at flying, as was famously pointed out by Richard Bach in his classic novella, Jonathan Livingston Seagull. Bach's novella is about Jonathan, a seagull who strives to be so good at what seagulls do best (flying) that he transcends his physical nature to become the perfect seagull. To quote Bach's work:
Most gulls don't bother to learn more than the simplest facts of flight...
Who is more responsible than a gull who finds and follows meaning, a higher purpose for life?
It isn't until Marco's misadventures are foisted upon him that he realizes he has a lot to learn about the world, and perhaps most of all, about himself, which brings us full circle back around to the odyssey theme.