swim the Thames

• cross the Thames

Variant of swim the Tiber, by substitution of London’s river Thames for Rome’s river Tiber.

swim the Thames (third-person singular simple present swims the Thames, present participle swimming the Thames, simple past swam the Thames, past participle swum the Thames)

1. (intransitive) To convert to Anglicanism.
   • 2019 March 11, Filip Mazurczak, “A Unique Credo and Affirmation of Faith by a Distinctive Mind”, in The Catholic World Report‎, Ignatius Press, archived from the original on November 29, 2022:

     […] Philip Jenkins, himself an ex-Catholic who swam the Thames, speculates that the rates of decline in his adopted Church are so steep that the last American Episcopalian may have been born.

2. Used other than figuratively or idiomatically: see swim,‎ the,‎ Thames.

• swim the Bosphorus (“convert to Orthodoxy”)
• swim the Forth (“convert to Presbyterianism”)
• swim the Rhine (“convert to Lutheranism”)
• swim the Tiber (“convert to Roman Catholicism”)