Wall Street Is Spending Billions on Marinas for Bigger Yachts (1)

On a rainy spring morning, Jack Brewer is watching workers prep boats for another season on Long Island Sound. In a world where yachts can stretch longer than a football field, the marina is relatively modest, handling boats that would max out at the 20-yard line. Here in the New York suburb of Mamaroneck, even the smaller craft are refined: bespoke Hinckleys, built in Maine with gleaming teak; powerboats bursting with the newest technology; and low-slung sailboats whose Italian designers relied on an older science in their pursuit of speed.

Brewer at the Post Road marina in Mamaroneck.

Photographer: Benedict Evans for Bloomberg Markets

Brewer, 84, started his business in 1964, back ...