Bay Pines Toastmasters Open House: Meet members and experience firsthand what Toastmasters do. 5 p.m. Free. Bay Pines VA Healthcare System, 10000 Bay Pines Blvd., St. Petersburg. (727) 398-6661.
Biodiversity: Gopher Tortoises: Field biologist George Heinrich will hold discussions about the important ecological role played by the gopher tortoise and how fire is crucial in maintaining populations of this threatened keystone species. 7 p.m. Free. Pinellas County Extension Service, 12520 Ulmerton Road, Largo. (727) 582-2100.
Taj Mahal: The musician named after the grand building plays the Palladium in a concert celebrating four decades of blues, roots and reggae. 7:30 p.m. $42-$55. Palladium Theater, 253 Fifth Ave. N, St. Petersburg. (727) 822-3590. spcollege.edu/palladium.
Intermediate Dog Training Series: This four-week course is designed to boost your dog's confidence. Instructors build upon foundational commands. 7 p.m. $45. SPCA Tampa Bay, 9099 130th Ave. N, Largo. (727) 388-0451.
Get Downtown First Friday Music Series: Get downtown for fun with music, food and a lively crowd all in the heart of St. Petersburg. Beer and wine sales benefit area organizations. 5:30-10 p.m. Free; refreshments extra. Second Street N and Central Avenue. (727) 393-3597.
Zumba party: The Seminole Recreation Center is having a Zumba Bash from 6 to 8 p.m. at the Holland G. Mangum Recreation Complex, 9100 113th St. N. The event is appropriate for all ages and abilities. $10 in advance, $15 at the door. Call (727) 391-8345 for information.
Boating Safety Course: The U.S. Coast Guard Auxiliary Flotilla 72 offers a safe boating program for adults and children at least 14 years old. Registration required: email firstname.lastname@example.org 8:30 a.m.-4:30 p.m. $24. Coast Guard Auxiliary 72, 1300 Beach Drive SE, St. Petersburg. (727) 898-1324.
Writers Group Meeting: Pinellas Authors and Writers Organization meets weekly at the Largo Community Center. Members read five minutes of their work, which is then critiqued by the group. Open to writers of all levels and all prose genres. 9:30 a.m. Free. 400 Alt. Keene Road. (727) 736-1026.
Vintage Car Show: Witness the evolution of cars at this showcase of nearly 75 different vehicles from the 1920s through the 1980s, then grab a bite from the food truck rally. 11 a.m.-2 p.m. $15. Armed Forces History Museum, 2050 34th Way N, Largo. (727) 539-8371.
Aquatic Center Grand Opening: Celebrate the reopening of the aquatic center at this party with giveaways and use of the slides. Noon-4 p.m. $12, $23 up to five people. Highland Recreation Complex and Family Aquatic Center, 400 Highland Ave. NE, Largo. (727) 518-3018.
Starting from Scratch Cat Workshop: This two-day workshop focuses on massage techniques, body language tips and cat harness demo. Cats welcome in carriers. 2 p.m. $15 adopter, $20 public. SPCA Tampa Bay, 9099 130th Ave. N, Largo. (727) 388-0451.
Tampa Bay Rays vs. Baltimore Orioles with a concert by Martina McBride: Purchase a $35 press level ticket and get specialty Italian food available for purchase and a Rays Italian hat. Stick around after the game for a performance by Martina McBride. 4:10 p.m. Tropicana Field, St. Petersburg. (888) 326-7297. tampabay.rays.mlb.com.
Rocky Horror Screening with Live Cast: A live cast, Interchangeable Parts, performs along with The Rocky Horror Picture Show while it plays on screen. Rated R. 11 p.m. Tickets $6; optional prop bags $1. Tri-City 8, 5140 East Bay Drive, Largo. (888) 262-4386. RHPSIP.com.