Here is a brief sampling of other adventure trips from the World Airways Hawaii Adventure Travel Directory, a comprehensive and regularly updated list of options that includes a brief description of services offered, addresses, and phone numbers. HORSEBACK RIDING

Ironwood Outfitters, P.O. Box 332, Kamuela, Hawaii 96743. 808-885-4941. On the Big Island.

Kaanapali Kau Lio, P.O Box 10656, Kaanapali Beach, Hawaii 96761. 808-667-7896. On Maui.

Pooku Stables, P.O. Box 888, Hanalei, Hawaii 06714. 808-326-6777. Kauai. BACKPACKING

Hawaii Bound, 825 Keeamoku St., No. 220, Honolulu, Hawaii 96814. 808-946-6502. Camping explorations on the big island. RAFTING

Kauai Zodiac, Papilon Helicopters, P.O. Box 608, Hanalei, Hawaii 96714. 808-826-6591. Exploring the Na Pali coast of Kauai in motorized rubber rafts. WINDSURFING

Aloha Windsurfing Hawaii, 2239 Aloha Dr., Waikiki, Hawaii 808-926-1185. On Oahu.

International Sailing Academy, P.O. Box 1729, Lihue, Hawaii 96766. 808-245-9290. Kauai. EXPEDITIONS

Earthwatch, 10 Juniper Rd., Box 127, Belmont, Mass. 02178. 617-489-3030. Work with scientists who are studying dolphin communication (four-week sessions) and sea bird colonization (two-week sessions).

The directory is expected to be available by the end of this month. For a free copy, write World Airways Hawaii Adventure Travel Directory, 918 16th St. NW, Washington, D.C. 20006.

Information on the islands also can be obtained from the Hawaii Visitors Bureau, 441 Lexington Ave., New York, N.Y. 10017. 212-986-9203.