Women’s 50 Fly Swim-Off Set To Happen Between Leah Shackley and Miriam Sheehan

2025 U.S. OPEN

The final morning of competition at the U.S. Open kicked off with the women’s 50 fly, and it will require a swim-off to determine who makes the A final.

Two NCAA stars – Leah Shackley of NC State and Miriam Sheehan, formerly of NC State before transferring to ASU – swam twin 26.97s in lane 5 of their respective heats. For Sheehan, this was her second best time ever, behind only the 26.56 she clocked this August at the Tyr Pro Championships in California. Shackley, meanwhile, has been as swift as 26.38 this season at the U.S. National Championships. Her lifetime best stands at 26.20, which she registered to win the event at the 2023 World Junior Championships.

The swim-off to determine who gets the A final spot will happen at the end of the preliminary session and race Olympic and World medalists Gretchen Walsh, Marie Wattel, and Mary-Sophie Harvey.

The swim-off adds a third swim to both of their mornings. Shackley swam the 200 back immediately after the 50 fly, in which she placed 5th. Sheehan, meanwhile, will swim the 100 free later on in the session.

Though Sheehan used to be part of the Wolfpack, the Puerto Rican Olympian never overlapped with Shackley. She became a Sun Devil at the start of the 2024-25 season, which is when Shackley arrived in Raleigh for her freshman year.

Results of the swim-off will be updated both here and on the session’s live recap.

Update: the swim-off did not happen, as it appears Shackley has renounced her A final spot.