6- and 7-year-olds finish the swim.
The event attracted more than 180 entries from children aged between 6 and 15 and hundreds of spectators watched keenly.
Different age groups raced various distances and organiser Victoria Murray-Orr called it a brilliant start for the week-long festival.
"All the kids were so amazing . . . There are some really keen triathletes out there which is great to see," Mrs Murray-Orr said.
"We saw kids helping their friends finish the race, crossing the line hand in hand and supporting each other."
