About Us
About Leinster Open Sea
Leinster Open Sea (LOS) is the home of Ireland's longest-running open water swimming series, delivering a full calendar of races from May to September, in partnership with our member clubs.
It is a not-for-profit organisation, with all revenue re-invested back into clubs and the race series. Our purpose is to provide safe, enjoyable and well-organised events while preserving and celebrating the unique community spirit that defines open water swimming.
We exist to nurture a vibrant, welcoming environment where swimmers of all ages and abilities can challenge themselves, connect with others, and experience the joy of racing in the open water.
Our experienced race operations teams and safety crews, manage carefully planned events to ensure that swimmers can push their limits in a well-managed, supportive environment.
Our Races and Locations
Every year we develop a comprehensive race calendar which aims to strike a balance between variety and challenge. The majority of races are 1.6-2.2km and located on/along the Leinster coastline, but also include some river and lake swims. From Wicklow Harbour to the Docklands, Howth to Killiney Beach, we race in some beautiful Irish waters.
Most races are run using a handicap timing system to provide all swimmers with an equal chance of winning. The calendar of approximately 30 races will always include:
- Club races – Clubs registered with LOS co-host races. The Clubs provide volunteers to support race operations on the day.
- Majors – Flagship races, in fantastic locations, with extra challenge, super prizes, a bite to eat and a bit of craic.
- Swim Series – Mass starts, mixed races; something a little different.
Our race trophies are very special as many honour and remember past swimmers who helped shape our history.
Sustainability
Leinster Open Sea is committed to operating in an environmentally responsible manner and minimising the impact of our activities on natural water environments and surrounding communities. As an open water swimming organisation, we recognise our responsibility to protect the beaches, lakes, rivers, and ecosystems that make our sport possible.
As a volunteer-led organisation with no physical premises, our sustainability approach focuses on responsible event delivery, resource use, and participant behaviour. Our Sustainability policy is available in our Documents section.
100+
Years of History
30+
Annual Races
1000+
Active Members