- Dixie Divers
- 633 people
- United States (Deerfield Beach)
The most participants in an underwater clean-up in 24 hours is 633, and was achieved by Dixie Divers (USA) in Deerfield Beach, Florida, USA, on 15 June 2019.
During the attempt more than 544 kg (1,200 lb) of trash was removed from the Deerfield Beach Pier by SCUBA diving participants. The trash largely consisted of fishing line and lead weights used in fishing.