Often rough. Strong current and/or wind. Avoid as a beginner.
Usually calm / sheltered. Good practice water.
Ferry route. Fast boats, 25–35 kn. Dashed lines are seasonal / event-day routes.
Ship traffic lane. Arrows show the direction ships travel in it. Stay out, or cross quickly at a right angle and behind ships.
Precautionary area. Ships merge and turn here. Be extra alert.
Dredged channel. Deep water kept open for big ships. They can't leave it, so you must not impede them.
Red marker (even number). Keep it on your right when returning (coming in from sea or heading upstream).
Green marker (odd number). Keep it on your left when returning.
Other marks (safe water, danger, special). Click one for details.
+Rock, wreck or obstruction. Give it room.
➤Current. Arrow points the way the water flows; length and color show speed.
▲Live ship. The line ahead shows where it will be in 10 minutes.
Away from channels (for example, leaving Pier 40) there's usually no lane to follow. Go by the
chart depth, the rules of the road, and the current. Red/green only matter where there's a marked channel.
Data: NOAA ENC charts, NOAA CO-OPS current predictions, aisstream.io. Not for navigation:
always cross-check with official charts, a proper chart plotter, and your eyes.