The move comes after the retirement of Tidey’s 49erFX skiff partner Andrea Brewster following last summer’s Rio games, where they finished 12th in the debut Olympic event for their class.
Tidey, who qualifies for British citizenship through her father, indicated that Ireland’s concentration on the Laser Radial and 420 classes prompted her to make the change.
“There wasn’t an option here in Ireland in the 49er FX with another girl who had the experience to sail at the same level … to be competitive and win a medal in 2020,” said Tidey, who is already training with her new partner, Rio top-10-placed Charlotte Dobson.
However, changing national representation in competition may not be smooth sailing for 23-year-old Tidey.
World Sailing rules dictate that three years must pass before sailing for one country and competing under another’s flag.
That means the soonest Tidey could compete for Britain at a world championship is 2019, unless the World Sailing Board makes an exemption in agreement with the relevant Member National Authorities.