The travel agent said that all the ships were booked up and things were very tight, but that he would see what he could do.
A couple of days later, the travel agent phoned and said he could now get them onto a three day cruise.
The guy agreed and went to the drugstore to buy three Dramamine's and three condoms.
Next day, the agent called back and said that he now could book a five day cruise.
The guy said, "I'll take it," and returned to the same pharmacy, to buy two more Dramamine's and two more condoms.
The following day, the travel agent called yet again and said he could now book an eight day cruise.
The guy agreed, and went back to the drugstore. He asked for three more Dramamine and three more condoms.
The pharmacist looked sympathetically at him and said, "Look, if it makes you sick, why do you keep doing it?"