SEVENTH ANNUAL HOUSTON INTERNATIONAL TRANSPORTATION FESTIVAL. May 18-20. Port of Houston's Turning Basin Terminal. (713) 226-2131.

RUDDER CLUB. May 19. New York. Annual dinner dance. Windows on the World. (212) 747-0512.WEBB INSTITUTE OF NAVAL ARCHITECTURE. May 19. Glen Cove, N.Y. Annual alumni homecoming. Webb Institute campus, Crescent Beach Road. (516) 759-2040.

AMERICAN ASSOCIATION OF PORT AUTHORITIES. May 20-25. Tampa, Fla. Executive management conference. Saddlebrook Conference Center. (703) 684-5700.

27TH INTERNATIONAL NAVIGATION CONGRESS. May 20-26. Osaka, Japan. Sponsored by Permanent International Association of Navigation Congresses. Royal Hotel. Contact: United States Section, PIANC, attn: CECW-PK, 20 Massachusetts Ave. N.W., Washington, D.C. 20314-1000. (202) 504-4312.

MARITIME DAY COMMITTEE. May 21. New York. Reception and buffet. Windows on the World, World Trade Center. (212) 466-8317.

U.S. MERCHANT MARINE MEMORIAL. May 22. Buzzards Bay, Mass. First annual National Maritime Day ceremonies and luncheon at Massachusetts Maritime Academy. Contact: Capt. Al Wilson. (617) 759-5761.

PROPELLER CLUB OF THE PORT OF WASHINGTON, D.C. May 22. National Maritime Day memorial service, wreath-laying ceremony and luncheon. Featured speaker: Vice Adm. Francis R. Donovan, commander of the Military Sealift Command. (202) 638-2405.

MERCHANT MARINE MEMORIAL SERVICE. May 22. Washington, D.C. Warren Leback, U.S. maritime administrator, will host the ceremony, which begins 10:30 a.m. on the west steps of the U.S. Capitol. If it rains, the service will take place in Room 2230 of the Nassif Building, 7th and D Streets, N.W. (202) 366-5807.

FISHER MARITIME TRANSPORTATION COUNSELORS INC. Three-day training program: ''Fundamentals of Contract and Change Management for Ship Construction, Repair and Design." May 23-25, Radisson Inn Seal Beach Hotel, Long Beach, Calif.; June 13-15, Lenox Hotel, Boston; July 11-13, Coast Georgian Court Hotel, Vancouver, British Columbia. (800) 732-3476.

PROPELLER CLUB OF THE UNITED STATES, PORT OF BOSTON CHAPTER. May 25. Boston. Annual Maritime Day luncheon. Guest speaker: John Stocker, president, Shipbuilders Council of America. Anthony's Pier 4 Restaurant. Contact: Carolyn White, (617) 381-8540.

U.S. MERCHANT MARINE ACADEMY ALUMNI ASSOCIATION. May 25. Houston. Luncheon meeting. Guest speaker: Warren Leback, maritime administrator. Brady's Landing Restaurant. Contact: Donald G. Brown, (713) 223-2322.

COMBAT MERCHANT MARINERS OF WORLD WAR II. May 27. Park Ridge, N.J. Victory dinner, reunion and celebration of Decoration Day. Marriott Resort Hotel, 300 Brae Blvd. (914) 623-8484.

INTERNATIONAL ASSOCIATION OF AIRPORT AND SEAPORT POLICE. May 27-June 1. Tacoma, Wash. Annual conference. Tacoma Sheraton Hotel. Contact: Roland Nease, conference coordinator. (206) 884-2025.

CONFERENCE ON MARITIME LAW AND INSURANCE. June 4-5. New York. Sponsored by World Trade Institute. Topics covered include chartering, drug enforcement regulations, legal aspects of oil pollution, maritime liens and bankruptcy, and cargo claims. World Trade Center. (212) 466-4044.

POSIDONIA '90 INTERNATIONAL SHIPPING EXHIBITION. June 4-8. Piraeus, Greece. Sponsored by the Seatrade Organisation. Piraeus Port Authority Exhibition Center. (609) 452-9414.

CHICAGO ASSOCIATION OF COMMERCE AND INDUSTRY. June 5. Chicago. The Shipping Act of 1984: Where Do We Go From Here. Chicago O'Hare Marriott Hotel, 8535 W. Higgins Road. (312) 580-6977.

AMERICAN PETROLEUM INSTITUTE. June 5. Washington, D.C. Forum on alternative tanker designs. Park Hyatt Hotel, 24th and M Streets. (202) 682-8193.

THE PORT OF THE FUTURE. June 6-8. Montreal. Seminar sponsored by American Association of Port Authorities. Queen Elizabeth Hotel. (703) 684-5700.

AMERICAN PETROLEUM INSTITUTE. June 10-13. Pebble Beach, Calif. Tanker Conference - Managing Change in the 1990s. The Inn at Spanish Bay. (202)


NORTH ATLANTIC PORTS ASSOCIATION. June 13-14. Portsmouth, N.H. Annual meeting. Sheraton Hotel. (302) 645-9732.

CALIFORNIA MARINE AFFAIRS AND NAVIGATION CONFERENCE. June 15. San Jose, Calif. Fourth annual summer seminar. What Happens When a Quake Hits the Shore? - Survival at the Water's Edge. A look at the experience of the Santa Cruz port district. Red Lion Hotel. (415) 982-7788.

TAX ASPECTS OF INTERNATIONAL SHIPPING. June 18-19. New York. World Trade Institute course includes information on most recent tax changes. World Trade Center. (212) 466-3165.

AGRICULTURE OCEAN TRANSPORTATION COALITION. June 22. San Francisco. Annual meeting. Airport Hilton. (202) 393-4460.

PORTLAND EXPO '90. June 22. Portland, Maine. First maritime conference sponsored by Port of Portland. Topics include the role of small ports in the evolution of U.S. trade with Europe, cruise ship calls, overfishing. Sonesta Hotel. Contact: Thomas Valleau, (207) 773-1716.