Lucy's missing the ship and her unconventional boarding is similar to the "I Love Lucy" episode "Bon Voyage" (S5;E13).
Originally, the episode was to be filmed aboard the real SS Lurline and on location in Hawaii. When costs proved prohibitive, Lucille Ball productions (LBP) had a three-quarter scale model of the ship built on the Paramount lot. At the time it was the second largest ship ever built at the studio. The sets occupied three sound stages. It even included a real swimming pool.
This episode was a single-camera shoot and filmed without a studio audience.
Hawaii was a favorite getaway destination of the Arnaz family. The Season 3 DVD contains home movie footage of the family (and friends) vacationing together in Hawaii.
The episode incorporates some establishing locations shots of the Lurline departing with the Golden Gate Bridge in the background. There is also a location shot of Lucy standing on a dock taking photographs. Because the Lurline sailed for the last time on June 25, 1970, the establishing shots had to have been filmed during April, May or June 1970.