I'm throwing a dinner party on a small cruise ship this summer. I'm thinking about dress code and what I should wear and expect people to wear. I've thought of making it semi-formal and wearing a white dinner jacket with black pants (satin stripe) and balmorals -- or finding a pair of velvet slippers! There are only so many events in life where you can legitimately wear the white dinner jacket. For the guests, I honestly don't expect anyone to show up in a tuxedo. For this reason, I'm not sure if "semi-formal" is the right way to go on the invitations. Likewise, it might feel too stiff if everyone shows up in black suits, considering it is a cruise. I'd prefer to convey casual. Perhaps "dressy casual"? I'm paranoid that people will show up in jeans, but might also be pleased to see more "boating appropriate", casual-like attire.