The June 14 hijacking of a TWA airliner from Athens resulted in a 20-30% loss of cruise passengers scheduled to sail to and from Pireaus, according to several sources within the industry.

While most cruise lines affected reported that they are not altering their itineraries, Ocean Cruise Lines announced that its Ocean Islander will now sail between Venice and Civitavecchia instead of Athens this summer. Similarly, Princess Cruises changed its June 25, July 7 and July 19 cruises between Naples and Athens to roundtrip sailings from Naples. According to Mike Hannan, Princess' vice president of marketing, there is an "excellent likelihood" that the line also will change its August itineraries.

Hannan also said that many passengers are altering their plans, rather than cancelling them altogether, choosing to postpone their vacations until fall or change their reservations to Alaskan and transcanal cruises.

Although several spokespeople were optimistic that the hijacking is negative effects would subside now that the crisis is over, they noted that passengers still are concerned about the safety of travel to Greece, and that steps are being taken to assuage their fears.

Among them is a full-scale promotional campaign being undertaken by Urban Associates in New York. According to George Doris, spokesman for Urban, an eight-page newsletter reporting on the safety of Greece is being sent to 28,000 travel agents in the United States and Canada; and a four-day press trip, scheduled for July 3, has been arranged for ten representatives from the television, radio and print news media. Fact sheets telling about the safety of cruise ships and the friendliness of the Greek people also are being distributed to community leaders, and free mini-cruises are being offered, as well.

The Greek National Tourist Organi­zation has been issuing numerous news releases combat the negative publicity, and is planning several press trips for the near future. A full-scale advertising campaign promoting Greece also is being considered for the fall.