Seattle is a popular destination for travelers, and of course a major cruise port for Alaska and Canada cruises. With many cruises leaving on Saturday late afternoons, you may not be able to find a Mass before departure, especially if the cruise line books your air. If traveling on your own, and you are arriving or departing a day earlier, you may be able to catch one either the day before or upon your return.
And, if you are on Holland America, they have a Catholic priest on all cruises so you will probably be able to attend Mass on Sunday at sea. Some other cruise lines have a Catholic priest on certain cruises. You can check them all here.
There are two cruise terminals in Seattle: Bell Street Pier and Smith Cove Cruise Terminal, so check with your cruise line to find out which one you will be sailing from.
As of 2018, Pier 91 terminal serves the ships of Carnival, Celebrity, Holland America, Princess, Disney and Royal Caribbean. Pier 66 terminal serves the ships of NCL Norwegian and Oceania.
For more details on the cruise ports of Seattle you can check Cruisemapper.com.
The map below will give you some of the nearest churches to the cruise port.
For seafarers, there is also a seafarers center sponsored by the Archdiocese of Seattle. They minister to seafarers on both commercial ships and cruise ships, who often are away from families for many months at a time.