Can someone explain how humans have adapted to living in marine biomes?

We haven't and we don't. Building cruise ships isn't the same as being adapted to living in a marine biome.

By "Marine Biome" I assume you are referring to any type of marine ecosystem, be this saltwater estuary, oyster beds, River deltas, etc. It could also refer to islands or atolls. If this is the case, then adaptation revolves mostly around living with the ocean, and using it for food (fishing, aquaculture etc) travel, (ships, ferries, sea planes) and knowing how to deal with possible environmental problems (tsunamis, high tidesetc). let me know if you have more specific questions,