More than 145 overseas participants will take part in the 21st annual Round the Sound Charity 10K Swim-A-Thon on Sunday.All swimmers are challenged to help raise funds for The Sunshine League, which was the Island’s first social service organisation.Event organisers, the Dolphin Swim Team and Bermuda Open Water Swimmers, are hoping to top last year’s record of 301 swimmers.The swim, which starts at the Aquarium at 10am, continues clockwise around the Harrington Sound.Entries can be found online at www.raceday.bm, www.roundthesound.bm, at the Sportseller in Washington Mall or International Imports on Par-La-Ville Road.Late entries will be accepted until 5pm on October 14.