Nassau/Suffolk Long Island Open Water Swim

The Nassau/Suffolk Long Island Open Water Swim is a 1609-meter charity event held in the Atlantic coastal waters off Long Island, New York. Organized by Swim Across America to fund cancer research, the annual swim takes place in an environment shaped by the Wisconsin glaciation, which carved the island's complex coastal terrain during the waning of the last Ice Age. Swimmers navigate these waters with the knowledge that this geography was first definitively mapped by the Dutch explorer Adriaen Block in 1615, when he established that both Manhattan and Long Island were distinct islands.

Historical waters and race day

The local history embedded in these waters dates back to the 17th century, when the Dutch West India Company facilitated a triangular trade involving wampum produced by Long Island Native Americans, a currency used to acquire furs from inland tribes. The shoreline itself saw the birth of the first permanent English settlement on the island in 1640, where Peter Hallock earned the privilege of being the first to land at Southold after a drawing of lots. While the open sea provides a broad arena for the swim, participants remain in a landscape where the conservation of local habitats, such as the brook and rainbow trout populations in the nearby Connetquot River, remains a point of regional pride. The event operates on a logistics-heavy model, managed by volunteers to ensure participant safety in open ocean conditions. For those looking to maintain their training throughout the season, it is common for participants to also enter the local Swim Across America charity events or the Cross Bay Swim to challenge their endurance in different coastal settings.