The Ironman race kicked off just after 7am this morning with over 2,000 people running, cycling and swimming through Dublin.
And what a morning for it.
If you're not taking part, but you are out and about, take note of the following closures and diversions that are in place...
Pedestrian access across all of the race routes should not be restricted, but take caution that roads are safe before crossing.
There will be no vehicle access across The Liffey in the city centre until some time after 10:15am. Drivers are advised to use the M50 as an alternative route for crossing the city during the race.
All surrounding roads will be closed until 10am.
The bottom of Booterstown Avenue will be closed until 10am.
There will be no access to Strand Road or Beach Road between 7am and 10am.
There will be no access on to Sean Moore Road between 7am and a little after 10:15am and the East Link Bridge will also be closed during this time.
Traffic travelling to the north side of the city should do so using the M50.
The course of the race will continue over the East Link Bridge and along North Wall Quay all the way up to Parkgate Street.
Traffic exiting the Port Tunnel will not be able to access the East Link Bridge or the North Quays until after 10:15am.
And if you see participants out and about give them a cheer.
'Cos it can't have been easy to get up at the crack of dawn for the race.