What reason did each friend put forth for his being against a sea -trip ? What was the actual reason?

J. suggests a rural, old-world spot, but Harris wishes to avoid remote locations and counters with the suggestion of a sea cruise. J. vetoes that idea because one week is not enough time to overcome seasickness and actually enjoy the trip. He notes to the reader that no one admits to being seasick on land, but that many people have trouble with it when actually on a ship.