There are plenty of reviews of this ship and itinerary (5 nights from Jacksonville, calling at Nassau and Half Moon Cay), so I wanted specifically to address the needs of vegetarians, vegans, or anyone who just doesn't want to go home heavier than when they came.
Full disclosure about me: I'm not a total vegan. I am vegetarian, which means I don't eat meat, fish or items made with meat/fish stocks, gravies, etc. I do avoid eggs, cheese and milk most times, though I occasionally can't pass up a bit of chocolate. I just feel better when I don't eat cheese and butter in particular.
Is it possible to eat well on this ship if you are vegetarian or vegan?
M18 was good -- spacious with two portholes and a sort of "window seat" that I probably wasn't supposed to sit in. It's pretty far forward, which means less noise in the hallways. You do get some anchor/engine noise, but I didn't mind.