Fifth annual Morton Plant Mease Triathlon: The Morton Plant Mease Triathlon kicks off at 6:50 a.m. with a one-third mile open water swim at Sand Key Park, 1060 Gulf Blvd., Clearwater. From there, participants will bike 13 miles through Clearwater Beach, over the Memorial Causeway and through Clearwater. The final leg consists of a 3.1-mile run in Sand Key Park. (727) 953-9198. www.pinellascounty.org/park/15_Sand_Key.htm.
Bark at the Ball Park IV: Take "man's best friend" out to a ball game! Fidos are welcome to join as you watch the Clearwater Threshers take on the Dunedin Blue Jays, check out adoptable pets, raffle baskets and even take a post-game run of the bases. Gates open at noon. The Humane Society of Pinellas benefits. 1 p.m. $5-$9 humans, $5 dogs. Bright House Networks Field, 601 N Old Coachman Road, Clearwater. (727) 467-4457.
'The Boys Next Door': A touching play by Tom Griffin about four mentally challenged men. 2 p.m. $18, $15 seniors/students/military. West Coast Players Theatre, 21905 U.S. 19 N, Clearwater. (727) 437-2363. wcplayers.com.
Dave Hardin in Concert: Dave Hardin, a roots musician and gifted songwriter, was twice awarded Best Songwriter by the Weekly Planet. Visit www.davehardinmusic.com. 7:30-9:30 p.m. Advance tickets $10. The Painted Fish Gallery, 350 Main St., Dunedin. (727) 734-5060. www.paintedfishgallery.com.
Itty Bitty Splashtime: Parents and caregivers can enjoy the companionship of others while their children ages 5 and younger enjoy the cool waters of the pool's splash area. 9:45-10:45 a.m. $1.50, 2 and younger no fee. Highland Recreation Complex and Family Aquatic Center, 400 Highland Ave. NE, Largo. (727) 518-3016. www.largo.com/department/division.php?fDD=13-61.
Skateboarding Lessons: All ages can learn tricks and skills with the skate park staff. All participants must provide their own equipment. Helmet required. Skate park registrations waiver and consent form must be on file at time of registration. 6-7 p.m. $25, $20 residents. Largo Skate Park, 400 Highland Ave. NE, Largo. (727) 518-3016. www.largo.com.
Barbershop Harmony: The Florida Suncoast Men's Barbershop Chorus is expanding its membership and looking for tenors, leads, baritones and basses who enjoy singing four-part barbershop harmony. 6:30 p.m.-8:30 p.m. free. Crossroads Christian Church, 1645 Seminole Blvd., Largo ((727) 736-7999). www.suncoastchorus.com.