The Sound Stays Warm

Nantucket swims on two oceans, the cold open Atlantic pounding its south shore and the shallow sound lapping its north, and it is the sound side, the gentle town-facing beaches where the island's children learn to swim, that carries the season past Labor Day, the shallow water having banked the summer's heat until the September swims run warmer than June's, calm, clear, and progressively private as the ferries carry the crowds home. The last swim of these pages takes its island form here, and the sound holds it open into fall.

The sound beaches are the island's mildest geography, long shallows over pale sand, the water warming across acres of flats on every tide, and the September program runs them at their best, morning swims in glassy water with the harbor traffic for scenery, the children's beaches empty of children and ideal for laps, and the water temperature holding the swimmable sixties well past the equinox in most years. The Atlantic side, per the island's standing counsel, turns to walking and casting as its surf sharpens with the fall.

The late swims pair with the island's finest stretch, per the shoulder doctrine of these pages, the inns at softened terms, the cranberry harvest flooding the bogs crimson in October per the harvest calendar, the scalloping season opening in the harbor, and the moors going rust and gold for the bicycle miles between swims. The last-swim date becomes, among the island's year-rounders, a point of cheerful competition, October claims defended with photographic evidence.

Swim the sound side daily through any September stay, log the water's slow retreat, and take the final immersion off the town beach at high tide with the church towers behind, which is the island's version of the series' ritual. Defend your date at dinner. The summer people swim in July because the calendar says to, per the island's oldest observation, and the September swimmers swim because the water is actually better, which the sound, warm and empty, confirms daily until it quietly closes the season.