Worth it if you want a near-private reformer class — six people max, taught by the founder, and the club for the rest of the day. Check the booking page first: it is a summer residency, so it is not there all year.

Mason Pilates

Aly Berger's athletic reformer studio, in residence for the summer in The Studio on the Montauk Yacht Club property — so a class can turn into a day on the marina. Signature classes cap at six ($75); privates are $250 and duos start at $350, both arranged by text rather than online. Reformers, towers, chairs, weights and props, modifiable for injuries and pregnancy. Ask at the front for a golf cart, or put 58 Star Island into maps to drive straight to the studio. Seasonal: a summer residency, not a year-round address.