The competition, organised by Plymouth Leander, is the first of a number of Mayflower 400 aquatic events to be held in run up to the big anniversary in 2020.
The three day competition, which starts on Saturday (May 27) and runs through to Monday, will take place in the 50-metre pool at the Plymouth Life Centre.
It’s a level one licensed meet and is open to all swimmers aged nine and over who meet the qualifying standards.
It has been named the Harwich Cup in honour of the Essex town which was the birthplace of the Mayflower – the ship which carried the Pilgrim Fathers from Plymouth to the New World in 1620.
The Harwich Mayflower Project is building a replica ship there for the celebrations in three years’ time.
A number of dignitaries from Harwich will be visiting Plymouth this weekend for the event including the town’s deputy mayor and a representative from the Harwich Mayflower Project.
Plymouth Leander’s head coach Robin Armayan said: “We are delighted to be included as a partner in the Mayflower 400 celebrations and hope to kick-start the aquatic events this weekend with a top class competition.
“We welcome everyone who is visiting the Ocean City for the event – in particular all of the swimmers and their families as well as the representatives from Harwich.
“We’re looking forward to a great weekend of racing and are excited to be playing a part in the celebrations taking place over the next three years.”
Plymouth Leander have also confirmed that their Primary Schools Gala on Friday, June 23, is also now a Mayflower 400 event.
The aim is to encourage grassroots swimming and community links.
The ‘Pilgrims Depart Gala’, as it will be called, will run in cooperation with the Plymouth Schools Sports Partnership, the City of Plymouth ASA and Everyone Active.