"Bike-the-Base": Third annual bicycle race, 8:30 a.m. April 12, Kaneohe Marine Corps Base, Dewey Square. Cyclists may choose a 20-mile bike race covering paved roads or a 12-mile mountain bike race consisting of paved and dirt paths. The Bike Shop will provide free bicycle safety inspections from 7 to 8 a.m. All bikes are required to pass a pre-race inspection and bikers must wear bicycle helmets throughout the race. Top finishers in four age groups will receive awards. Pick up race numbers and packets from 8 a.m. to 4 p.m. April 9-10, Athletics Office, Building #1071. Entry fee: $15. A late fee of $5 will be charged for entries received after April 4. Call 254-7591 or 254-7596.
Harbor cleanup: Ala Wai Boat Harbor, 8 a.m. April 5, Harbor Master's Office (between the third and fourth row of boats behind the Ilikai Hotel). Wear sturdy shoes with gripping soles. Bring water, sunscreen, gloves and a hat. Call 591-3855.
Art classes: Weekly pencil, acrylic and oil painting classes with Patrick Ching begins April 5, Naturally Hawaiian Gallery, 41-1025 Kalanianaole Highway in Waimanalo. Limited enrollment. Register at 259-5354.
Archaeology of Moleka and Upper Makiki: State archaeologist Alan Carpenter leads a tour to Hawaiian agricultural sites, 8:30 to 10:30 a.m. April 5. Must be 8-years-old or older. Sponsored by the Hawaii Nature Center. Cost: $7. Reservations at 955-0100.
Acting for children: Ann Hamilton Ogilvie teaches two Level I acting classes for children ages 6-13. The first class, for ages 6 to 8, will be held from 9 to 10 a.m. and the second class, for ages 9 to 13, will be held from 10 to 11 a.m. Saturdays, April 5 to June 7.
Annie MacLachlan teaches the Level II class, 11 a.m. to midnight Saturdays, April 5 to June 7. Entry to the Level II class is by audition or recommendation of the Level I class instructor.
All classes will be held in the Diamond Head Theatre Annex, 4310 Diamond Head Road. Enrollment limited to 15. Fee: $80. Register at 734-8763.
Tap classes: Nancy Jensen will teach the steps, combinations and techniques most closely associated with Musical Theatre, Saturdays, April 5 to June 7. Beginning classes, 10 to 11:15 a.m.; and intermediate classes 8:45 to 10 a.m.=
All classes will be held at the Diamond Head Theatre Rehearsal Hall. Fee. $100. Register at 734-8763.
Broadway Jazz: John Rampage, winner of 17 Po'okela Awards, will teach several dance styles for people ages 18 and over, 11:15 a.m. to 12:30 p.m. Saturdays, April 5 to June 7, Diamond Head Theatre Rehearsal Hall. Enrollment limited to 20. Fee: $110. Register at 734-8763.
Jazz classes, led by Andrew Sakaguchi, for teens ages 12 to 17 will be held from 5 to 6:15 p.m. Mondays, April 7 to June 9, Diamond Head Theatre Rehearsal Hall. Enrollment limited to 20. Fee. $105. Register at 734-8763.
"Do Re Mi": Gain more self-confidence and a better understanding of vocal techniques and dynamics, Mondays, April 7 to June 9. Classes for children ages 7 to 11 will be held from 5 to 6 p.m.; and classes for people ages 12 and up will be held from 6 to 7 p.m. Enrollment limited to 20 students per class. Cost: $125. Register at 734-8763.
Set Design and Construction: Paul Guncheon will give a hands-on approach to set design, 7 to 9 p.m. Tuesdays, April 7 to June 10, Diamond Head Theatre Scene Shop. Guncheon won 8 Po'okela Awards for scenic design and has worked on the TV series "Marker," the film "Picture Bride" and many TV commercials. Fee: $125. Register at 734-8763.
Flamenco Dance: Mary Jill Ackerman will cover rhythms, posturing, arm-and-foot-work and the most popular Flamenco dances. Beginning classes, 5:30 to 6:45 p.m. Wednesdays, April 9 to June 11. Intermediate classes, 12:45 to 2 p.m. Saturdays, April 5 to June 5. Classes will be held in the Diamond Head Theatre Rehearsal Hall. Enrollment limited to 15. Fee: $80.
Acting for Adults-Intermediate: 7 to 9 p.m. Wednesdays, April 9 to June 11, Diamond Head Theatre Annex. Students will focus on refining acting skills and scenework, and will cover the areas of ensemble performance, understanding the dynamics of a scene, and reading a scene for text and subtext. Fee: $125. Register at 734-8763.
"Opus 17": Four-mile Honolulu Symphony Fun Run presented by the Symphony Guild, 7:30 a.m. April 27. Entry forms are available at all Aloha Petroleum gas stations and mini-marts, military exchanges, public libraries, Barnes and Noble, Borders Books and Music stores, Starbucks, Coffee Manoa, running stores and bike shops, Sacred Hearts Academy, Honolulu Club, Blood Bank, the March/April issue of Hawaii Race magazine, the Honolulu Symphony Offices or call 545-2588. Entry fee: $18 before April 7; $25 after April 7.
Tai Chi Chuan: Chinese art reducing anger and stress, and increasing softness and flexibility, 4:30 to 5:30 p.m. Mondays and Thursdays in Kekela Gym, Queen's Medical Center. Cost: $35. Register at 547-4780. For other classes, visit the center's Web site at http://www.queens.org.
Honolulu Marathon Clinic: Weekly jogging program with Dr. Jack Scaff Jr., 7:30 a.m. Sundays, Kapiolani Park Bandstand. James Honke leads a 6:30 a.m. program Sundays, Wahiawa Recreation Center.
Taiko classes: The Taiko Center of the Pacific offers classes through Kapiolani Community College. Call 737-7236.
Hawaii In-Line Skating Association: Workouts 5:30 p.m. weekdays at Kakaako Park. Call 988-5299.
Free hike to Diamond Head: Meet the Clean Air Team at the Honolulu Zoo entrance, 9 a.m. Saturdays. Three miles to the top. Call 948-3299.
Honolulu Community Drum Circle: Drummers, percussionists and dancers gather, 1 to 5 p.m. Saturdays, Keehi Lagoon Park. Potluck. Call 377-DRUM (377-3786) to confirm location each week.
Hash House Harriers: Social runs with Aloha group 3 p.m. Saturdays; call 948-AHHH (948-2444). Or Honolulu group 5:30 p.m. Tuesdays; call 948-HASH (948-4274).
Honolulu Marathon Clinic: Free training runs with Jack Scaff and staff, 7:30 a.m. Sundays, Kapiolani Park Bandstand. Call Norm at 247-4957. No meetings on three-day weekends.
Night reef walk: Waikiki Aquarium staff talk about ocean creatures and their habitat on a tour of the reef, April. Costs $8 adults, $7 children. Register by mail. Call 923-9741.
Sports Acrobatics Hawaii: Hawaii Highflyers Trampoline Club for adults and kids, 4 and 5 p.m. Mondays and Wednesdays, McCully Recreation Center. Call Karl Vorwerk at 949-3747.
Waikiki Acrobatic Troupe meets 4 p.m. Sundays at the beach across Kapiolani Park Bandstand; free workout at UH Studio Four 8 p.m. Wednesdays. Call Don Heafner at 536-7205.
Ikebana classes: Lillian Koide teaches flower arrangement 9 a.m. to noon Wednesdays at the Japanese Cultural Center. Tuition $30 per month plus supplies. Call 537-5765, evenings.
Honolulu Zoo: Zoo opens at 8 a.m. on the first and third Wednesdays of the month. General admission $6; $2 with Yum Yum Tree senior card. First Wednesdays feature a botanical tour at 8:45 a.m. for $2 more. Third Wednesdays, tai chi practice begins 8 a.m. Call 971-7174.
Nature Conservancy hikes: Two guided hikes a month to Honouliuli Preserve, home to more than 45 rare native plants and animals. Donation. Call 537-4508.