We bring both our tuxes and off white shawl collar dinner jackets on every cruise so we have a bit of variety, and regardless of what other say about weight restrictions and packing....We have never had a problem.
Norm is correct. Formal trousers are the appropriate companion to the jacket, along with braces ( suspenders ).
The interpretation part.....belt, or cummerbund? tie color? pocket square? pleated shirt or flat front ( ruffles ARE passe
), mother of pearl buttons or studs? choice of cufflinks?
Heck, I even had a pair of tuxedo trousers cuffed...usually they are straight legged, but I thought as long as its a tux, a subtle change might be interesting, and it is.
Just remember to stay away from the 'Fake' tux. Black pants off the rack with a black blazer ......a dark or black suit with a pleated shirt and bow tie...
If its not a tux, don't make it look like one, it doesn't work. A dark suit is fine with the dress codes on most ships now a days, pick out a nice shirt and tie and go with it as it is, not something it isn't.