The Portsmouth Try a Tri event returns tomorrow in Southsea.
A total of 200 juniors will be racing in the Tristars, while around 300 adults will take part in the sprint distance and super sprint distance.
Portsmouth City Council organise the triathlon and have seen it grow in popularity again this year, with all places sold out.
Great Britain age-group internationals Debbie Hallett and Neil Collins are among those set to compete in the sprint distance.
Collins has enjoyed an excellent summer so far with two wins in the Portsmouth Duathlon Series and age-group success in the Eton Dorney Triathlon.
Hallett is a member of Portsmouth Triathletes, while Samantha Rose, from Southsea, is another very talented triathlete who is set to take part.
Races begin with a sea swim from the beach, between South Parade Pier and Southsea Castle, then a cycle on traffic-free roads along the seafront, before finishing with a run along the promenade.
Tania Almond, Triathlon Development Officer for Portsmouth City Council, is hoping to see large crowds turn out to cheer on the competitors.
She said: ‘It’s a great spectacle so hopefully people will come and watch, especially as we have a very competitive field, including a couple of European qualifying age-groupers and some very good young athletes.
‘The popularity of the sport is definitely still on the increase.
‘This is the second year the event has been selected by the Triathlon England regional committee to be part of the youth series, so we are already becoming established as a quality event.
‘We’ve even had two entrants from as far away as Melbourne, in Australia.’
The sprint distance is a 750m swim, a 20k bike, and a 5k run, with competitors starting in waves from 11am.
Then the super sprint – a 400m swim, 10km bike and 2.5km run – starts at 11.45am.
Tristar races begin from 1pm. There are also duathlon races and a team relay.
Four teams from Mayville High School, including a visiting lecturer from Australia, will raise funds for Macmillan Cancer Support.
For more details see portsmouth.gov.uk/ext/events-parks-and-whats-on/events/portsmouth-triathlon.aspx
– DAVID BRAWN