Ayden Tan Shatters 11-12 National Record in 100 Yard Backstroke! (2025)

2025 East Bay Silver Dolphins Short Course C/B/BB+

• September 13-14, 2025
• Hercules Swim Center, Hercules, California
• Short Course Yards (25 yards), timed finals
• Full Meet Results

In his last meet as an 11-12,Ayden Tanfrom San Ramon Valley Aquatics in California took down one last National Age Group Record before aging up. This time, he broke the 100 backstroke record that was set by another CaliforniaRonald Dalmacio in 2016.

Tan posted a 50.76, which undercut Dalmacio’s prior mark of 50.99. Tan’s previous best of 51.11 ranked him 2nd all-time in the age group. That swim was done in January of this year.

No splits were available for Tan’s latest swim.

Fastest 11-12s in US history, 100 SCY Backstroke

1. Ayden Tan, SRVA – 50.76 (2025)
2. Ronald Dalmacio, Rose Bowl Aquatics – 50.99 (2016)
3. Vinny Marciano, Morris County Swim Club – 51.40 (2014)
4. Ethan Wang, Unattached – 51.63 (2025)
5. Brett Freyerick, NCAP – 51.95 (2016)

Tan, who swims for San Ramon Valley Aquatics, has been on a record-breaking streak this summer. He alsobroke the 100 yard IM record in Rohnert Park, California in mid-June, the200 meter IM record in early July, the100 meter free record in July in Santa Rosa, the 50 meter fly and 200 meter IM records in July, and the 50 meter free record in early August. This gives him seven total 11-12 National Age Group Record swims in summer 2025, which add to his five National Age Group Records in the 10 & under age group from 2023.