Australia's Olympic triathletes are rolling with the punches after the men's race was postponed for 24 hours and the spectre of a duathlon continues to loom.
Ongoing concerns over water quality in the River Seine have forced the organisers' hand, after swim training for the triathletes was cancelled on Sunday and Monday.
The men's triathlon is now scheduled for 10.45am local time (6.45pm AEST) on Wednesday, with the women's event slated for 8am.
But it remains unclear whether the two races will be swim-bike-run, or run-bike-run.
Forecast rain for Wednesday afternoon, which would further affect water quality, means a narrowing window for race organisers. The mixed team relay is scheduled at the same Pont Alexandre III race site on August 5.
"It's tricky, isn't it, when the weather becomes the one thing that dictates how competition can go for a sport," said Australian Olympic team chef de mission Anna Meares.
The persistent rain that marred the opening ceremony and day one of competition has forced the postponement, which was decided only hours before Tuesday's scheduled start.
"We've come through a pretty adaptable period in life, with COVID-19. We've had a couple of events this year postponed or cancelled this year with an hour's notice," said team coach Dan Atkins.
"Our guys are really adaptable."
Swim issues are no surprise for triathletes - Atkins noted an event in Port Douglas a couple of years ago was affected when a crocodile was spotted in the water.
The postponement meant Australia's entrants Matt Hauser and Luke Willian enjoyed an extra three hours' sleep.
Asked three days ago if he would swim in the Seine, regardless of the water quality, Hauser replied "bloody oath".
Changing Wednesday's races to duathlons is a nightmare scenario for organisers, especially as more than one billions euros ($A1.7 billion) have been spent on improving water quality in the Seine as a major Olympics legacy project.
Friday remains a contingency day.
"The beautiful thing about our sport is we get to showcase where we are, every time," Atkins said.
"Sydney - swimming in front of the Opera House, Beijing was in front of the presidential palace.
"We have an opportunity to swim and ride and run hopefully around the Arc de Triomphe, up the Champs Elysees, have the Eiffel Tower in the background.
"(But) if we have to park the swim, we'll just park the swim."
Race organisers said the water quality had improved, but the pollution readings at some points on the swim course were still too high.
"While we know this wasn't the result everyone wanted, we knew these contingencies were in place," Meares said.
"The most important thing that has happened here is that the welfare and well-being of the athletes has been taken into consideration.
"We do believe this won't affect their performances ... they have been ready for this."
- with PA