It is remarkably easy to live in New York City for five years and forget that four of the five boroughs sit on islands—and that only the Bronx is attached to the North American mainland. Because we spend our weekdays descending into subterranean subway stations, we often ignore the 520 miles of coastline right outside.

Reclaiming New York as a maritime city requires mastering two of the greatest transit bargains in the Western Hemisphere: the completely free Staten Island Ferry paired with the Staten Island Railway (SIR), and the six-route NYC Ferry fleet.

Start at Whitehall Terminal at the southern tip of Manhattan. Every fifteen to thirty minutes, 24 hours a day, the monumental orange boats of the Staten Island Ferry cast off for a five-mile, 25-minute crossing of Upper New York Bay to St. George. It costs zero dollars, has no turnstiles, and gives you an unobstructed promenade deck view of Ellis Island, the Statue of Liberty, and Governors Island.

Once you dock at St. George Terminal, don’t just turn around—walk straight down to the Staten Island Railway (SIR) tracks inside the terminal (where your tap counts as a free subway-to-SIR transfer within two hours) or board the S51 bus down Bay Street to Fort Wadsworth.

Standing at the narrows where Upper and Lower New York Bay meet beneath the towering 693-foot steel towers of the Verrazzano-Narrows Bridge, Fort Wadsworth is one of the oldest military installations in the United States, continuously fortified since a seventeenth-century Dutch blockhouse. Today part of Gateway National Recreation Area, its granite subterranean batteries, coastal bluff trails, and Overlook Park offer a jaw-dropping vantage point watching mammoth container ships glide beneath the bridge into New York Harbor.

For the return trip—or any sunny afternoon commute—download the NYC Ferry app. For a $4.50 single ticket (or $2.90 per ride when you buy a 10-trip pass), you can ride the St. George route up the Hudson River to Battery Park City and Midtown West, or hop the East River and South Brooklyn routes linking Wall Street/Pier 11 to DUMBO, Red Hook, Williamsburg, Greenpoint, and Astoria with an open-air upper deck and an onboard snack bar.