The Harlem River is an interesting eight-mile-long piece of water that flows from the East River at Hell Gate north to the Hudson River about two miles north of the George Washington Bridge. Although there are no marina facilities along the way, the river does shave off 20 miles versus traveling around Manhattan into the East River.
Along its length, the Harlem River is crossed by 15 bridges, and the controlling vertical clearance is 24 feet. If your vessel is less than 24 feet tall, you will only need to open the Spuyten Duyvil Railroad Swing Bridge (pictured above) at the confluence of the Harlem and Hudson Rivers. The bridge tender monitors VHF Channel 13 and will open the bridge on request if there is no rail traffic approaching. If your boat is taller than 24 feet, you will need to make four-hour advance arrangements to have all of the bridges opened for you, but keep in mind that they will not open the first bridge until after 10 a.m., and you must finish the passage by 5 p.m. Call the New York City Department of Transportation to make arrangements (212-371-7836).
Use NOAA Chart 12343.
There are no aids to navigation marking the opening of the Harlem River where it pours into the Hudson, but you cannot miss the Spuyten Duyvil Railroad Swing Bridge that closes off the mouth of the river. The bridge opens on request as long as there is no rail traffic approaching, and the bridge tender can be hailed on VHF Channel 13.
Once inside the river, keep in mind that the rivers tide floods to the south and ebbs to the north. If you can (depending on whether you have to have bridges opened or not), try and schedule your passage with a favorable current. If you do end up transiting the river during a foul current, remember to give yourself and others plenty of room at bridge crossings.