The challenge will take place at Anglesea Street Fire Station and teams will race the combined length of the River Lee and Liffey.
The Lee-FFey row will be undertaken by the 33 newest recruits who started their training in June.
17 will take part in the challenge from Dublin, while 16 recruits will travel to Cork.
Members of the public are encouraged to call to the fire station on Anglesea Street from 1pm to cheer on the recruits.
Good luck to CCFB recruits who challenge @DubFireBrigade recruits in aid of this fantastic cause. @BUMBLEance. May the best time win #Cork #teamwork https://t.co/irdHEFRdu8 #iDonate_ie
— Cork City Fire Brigade (@CorkCityFire) September 25, 2022