Festivities began Wednesday with the Parade of Ships and will continue through Memorial Day, when the main celebration will be held.
This is the 28th Fleet Week.
Ship tours will be conducted daily throughout the week in Manhattan, Brooklyn and Staten Island, with dozens of ships docked around the city.
Five U.S. Navy ships, four U.S. Naval Academy Yard Patrol boats, two U.S. Coast Guard cutters and four Royal Canadian Navy ships will participate in this year's event, with an expected 4,500 military personnel expected to take part.
And that means it's "hello sailor" time in New York City.