Hawaii Golf Expo '96: New merchandise, seminars with PGA pros Jerry King and Desmond Mahoney, and driving cages and putting greens, 9 a.m. to 6 p.m. Saturday, Blaisdell Exhibition Hall. Admission $4 general, $3 seniors, free for children accompanying an adult. Call 533-4165.

Pu'u O Hulu hike: Fred Dodge of the Hawaiian Trail and Mountain Club leads the way up a mountain by the sea, 7 a.m. Sunday. Costs $2. Call 696-4677.

"A Day in the Sun": Bouldering contest and beach clean-up, 8 a.m. to 6 p.m. Sunday, Waimea Bay, North Shore. Hat, sunscreen, drinking water and gloves recommended. To enter the contest, register at the Patagonia store in Haleiwa or Powder Edge at Aloha Tower Marketplace; entry fee $15. Call 637-1245.

Na Pohaku O Makiki: Visit rocks special to the ancient Hawaiians, 1:30 to 3:30 p.m. Sunday. For ages 9 and up. Costs $5. Call the Hawai'i Nature Center at 955-0100.

Chinese martial arts: Register by Wednesday for classes for men and women Saturday mornings or

Wednesday evenings at Wahiawa General Hospital. Styles include Bruce Lee's Jeet Kune Do ("Way of the Intercepting Fist"), tai chi ("Push Hands") and Wing Chun kung fu ("Sticky Hands"). Instructor is Rev. Christopher K. Eng of Waipahu United Church of Christ. Costs $20 to $30. Call Medy Eballar at 621-4380.

Learn to swim: The American Red Cross has free classes for children on Saturday mornings and adults on Monday, Wednesday and Thursday evenings at Ala Moana Beach. Call 734-2101 ext. 123 or 124.