SOUTH AFRICA NOTES A GAIN IN TOURISM. The South African Tourism Board said figures for the first nine months of 1987 (the latest period under survey) showed a 13 percent gain over the same period in 1986. The number of international visitors had been declining in recent years. SEE THE PANAMA CANAL (SOME OF IT, ANYWAY). Regency Cruises announced that its cruise ships will continue to include a partial transit of the canal during this period of unrest. Passengers aboard the Regent Star and Regent Sea will be able to pass through three stages of the Gatun Locks, proceeding to Gatun Lake, before returning to the Caribbean Sea. ``The ships do not stop in any Panamanian port, and therefore passengers are not affected in any way by the internal situation in Panama,'' said William Schanz, chairman and chief executive officer of the New York-based firm. SOME 95 PERCENT OF FEMALE CORPORATE EXECUTIVES do not travel for business, according to a survey by Damin Aviation, a helicopter charterer based in New Jersey. The survey was directed to more than 100 corporate travel managers at Fortune 500 companies. ``Although women have quickly climbed the corporate ladder and have risen to powerful ranks, our data reveal a low percentage of them actually going on business trips,'' said Anthony Amanzio, sales vice-president of Damin. COSTS OF TRAVEL WENT UP about 16 percent in 1987, as measured by the Runzheimer Business Travel Price Index. The index had leveled off during the previous year. ``The big increase is mostly due to rising costs in air travel,'' said Brad Burris, a vice-president at Runzheimer International, a consulting firm based in Rochester, Wis. Discount fares were less available, Mr. Burris said, and business travelers had difficulty fitting their schedules into the smaller number of low-fare flights. TO BETTER SERVE GERMAN VISITORS a city tourist brochure entirely in German is offered by the Washington, D.C., Convention and Visitors Association.