Endurance swimmer Lewis Pugh swims near the Edgartown Harbor Light, Thursday, May 15, 2025, in Edgartown, Massachusetts.

Endurance swimmer Lewis Pugh fist bumps a beach-goer before entering the water to begin his swim around Martha's Vineyard, Thursday, May 15, 2025, in Edgartown, Massachusetts.

Endurance swimmer Lewis Pugh prepares for his swim, Thursday, May 15, 2025, in Edgartown, Massachusetts.

Seals watch endurance swimmer Lewis Pugh near the Cape Poge Lighthouse, Thursday, May 15, 2025, in Edgartown, Massachusetts.

An instrument that sends an electronic signal into the water to ward off sharks is attached to a kayak near endurance swimmer Lewis Pugh, Thursday, May 15, 2025, off Edgartown, Massachusetts.

Endurance swimmer Lewis Pugh pauses to rehydrate during the first day of his swim around Martha's Vineyard, Thursday, May 15, 2025, off Edgartown, Massachusetts.

Endurance swimmer Lewis Pugh swims off the coast pf Edgartown, Massachusetts.

Kayaker Nicholas Burden guides endurance swimmer Lewis Pugh as a fishing boat passes by, Thursday, May 15, 2025, off Edgartown, Massachusetts.

An app is used to monitor endurance swimmer Lewis Pugh's temperature while he swims in 47 degree F water, Thursday, May 15, 2025, off Edgartown, Massachusetts.

Endurance swimmer Lewis Pugh answers questions about his planned swim while chatting with visitors to Martha's Vineyard, Thursday, May 15, 2025, in Edgartown, Massachusetts.