One of the most frequently asked questions you hear is: When is the best time to transit the East River? This question really has 3 answers depending on whether you are looking to: (1.) Transit Hell Gate at slack water, (2.) Transit the Entire East River with a fair current, or (3.) If you are truly masochistic; transit the East River against a foul current. Here we will concentrate on the first 2 options and leave the 3rd for those who derive their pleasures shall we say... "strangely".
Planning your passage through the East River can be beneficial for any vessel and it becomes almost imperative for low powered vessels. Making your passage of the East River at the incorrect time can result in your motoring along at a comfortable 7 knots and only making 2 knots over the ground. This can make a simple 14 NM trip 5 to 7 hours long. On the other hand picking the right time can result in speeds over the ground, in places, of 10 to 12 knots and a quick passage through the river.
Once you have decided how you want to transit the East River, whether you are shooting for slack water at Hell Gate or riding a fair current for the entire passage, you can start working on the solutions.
Current diagrams of the East River based on high and low water at The Battery in NYC: