Defining Steampunk is somewhat subjective, but most people see it as Victorian era science and society creating future tech. Steam-powered robots. Tesla coil activated ray guns. Wind-up, flying battleships. All this with Victorian social styles and an idealized sense of Victorian honor.
But the genre isn't extremely well defined which allows a great deal of latitude when it comes to what someone can do. A lot of the larger tech - the zeppelins with ray guns - aren't things that anyone can carry around or, indeed, realistically expect to make. But the lure of it is using one's imagination to create a unique "character" with all the trimmings. One can become Booster Cogwheel, Tesla Ranger with his trusty SPPARG (Steam-powered, pump-action rail gun) keeping law and order in the American west of 1890. Or they can become Lady Gearimina Worthington, representing Her Majesty's Flying Crusaders who does mortal battle with Slash McGillian of the Darwinists whose steam-powered android army threatens to overwhelm London. It's much like cos-play, role-playing and just the fun of creating one's look shared among others with the same passion for creating their own character.
Another kind of thing much the same are the Furries - creating an animal costume. It's still quite big, but not quite as visible as steampunk. One can walk around in Victorian clothing without really attracting a lot of attention. Not so much wearing a wolf outfit, or something like that. But both share many of the same motivations - creating a character that tends to resonate with the individual.
Or just showing off.
Yes, it's kind of "out there", but if people enjoy costuming up for Halloween, then this gives them an excuse to assume another personality and background - and have fun - a lot more often than once a year.
Either way, I'd love to go on that cruise.