How to lock through
What you need to know to pass through a lock safely
Stay away from restricted areas when approaching locks and dams. Don’t anchor in front of a lock or in the channel. Never tie off to a navigational buoy, and don’t cut in front of tow boats to be first into the lock. The lockmaster will decide lockage priority. Commercial vessels have right-of-way over pleasure craft.
Let the lockmaster know you want to lock through by pulling the signal chain or pushing the signal button, usually found in a ladder recess on the lock wall, or hail the lockmaster on your VHF-FM marine radio.
When using radio, ask the lockmaster for an estimated lock-through time. Leave your radio on the same channel, so the lockmaster can tell you when to enter.
If you don’t have a marine radio, watch the signal lights near the lock entrance and listen for the whistles. Red indicates that the lock is unavailable, so stay clear. Amber indicates that the lock is being readied, so stand by. Green indicates that the lock is ready. While waiting, figure out which side of your vessel you will secure to the lock and put out your fenders on that side.
The lockmaster sounds a long whistle blast when it’s time to enter the lock. For a twin lock, the lockmaster gives two long blasts for riverside and one long blast for landside.
Enter the lock at no-wake speed, and pull forward to allow other boats to fall in behind you. Usually, lock personnel show you where to pull up and give you the lines. Secure your vessel by taking the line to an outside cleat. Take a turn around the cleat so you can loosen or tighten the line as needed. Taking the line to the outside of your vessel keeps it to the wall with more control.
Don’t tie the lines to your vessel. Take in or pay out the line as the water level rises or falls. Turn off your engine after securing your vessel during lockage. Everyone aboard should wear life jackets.
When the lockage is complete, the lockmaster gives one short blast to signal permission to leave. For a twin lock, the lockmaster gives two short blasts for riverside and one short blast for landside. Leave at no-wake speed.
Afterward, thank the lockmaster over the radio or with a friendly wave.