Ironman announced today a new protocol that will be implemented for the 2019 Ironman World Championship swim start. For the first time, the world championship event will utilize a wave start that separates the field into 11 groups. Like in previous years, the professional men’s field will start at 6:25 a.m., followed by the professional women’s field at 6:30 a.m.

The PC/Open Exhibition and Handcycle divisions will then begin their day at 6:35 a.m. The first age group wave will start at 6:55 a.m. and continue every 5 minutes until all athletes are in the water.

“The swim start change is a reflection of, and reaction to, the extraordinary ability of our Ironman World Championship athletes,” said Andrew Messick, President & CEO of Ironman. “While we appreciate the simplicity and iconic visual of the mass start, our primary responsibility is to create a fair race for all athletes. A single start each for age-group men and age-group women creates too much density on the bike course.”

Ironman says the decision to move to an extended wave start was made following a comprehensive analysis of athlete data with the goal of reducing peak athlete density flowing onto the bike course. The new start times will not change the existing cut off standards for the Ironman World Championship – 2:20 for the swim and 10:30 for the bike. Athletes will also still have to reach the finish line within 17 hours to be official finishers of the race. This means the race will officially conclude at 12:30 a.m., with each athlete facing individual cutoff times based on their starting wave.

The change follows several moves by Ironman at its races to increase athlete safety and reduce course congestion. Many Ironman and 70.3 events now utilize a “rolling start,” where athletes self-seed based on their anticipated swim finish time. Ironman chose to keep athletes grouped by their division for the Ironman World Championship, most likely to allow athletes to race head to head for world titles.

See the new start times below.