New York Harbor is hosting what organizers are calling the largest maritime and aerial gathering in U.S. history this week, as part of Sail4th 250, a week-long celebration of America’s 250th birthday running July 3 through 8. For Brooklyn readers, the most direct way in is free: five historic vessels from four countries will be docked at Brooklyn Bridge Park starting today, with free self-guided deck tours available Saturday through Monday.

Today, July 3, 24 Class B tall ships (traditionally rigged vessels under 131 feet long) are parading down the East River from Hell Gate, pausing near South Street Seaport at 1 p.m. before proceeding to an anchorage at Gravesend Bay off Brooklyn, according to Long Island Press. The main event is tomorrow: more than 40 Class A ships, the largest category of tall ship at roughly 160 to 370 feet, enter the harbor under the Verrazzano-Narrows Bridge starting at 9:30 a.m. and sail north up the Hudson for about 2.5 hours, with each vessel passing roughly six minutes apart, according to AMNY.

The U.S. Coast Guard cutter Eagle leads the fleet, which represents nations including Italy, Peru, Portugal, India, Germany, Colombia, Romania, France, Spain, Argentina, and more, according to NBC New York. Ships can be tracked live at aquamap.app/sail4th-250.