Locks: How They Operate and How To Use Them
What is a Lock?
By learning how to use locks, you will have a host of new opportunities for pleasure boating on the rivers of North America. Lock attendants are present at most locks to help you through safely.
A series of dams on a river help maintain enough water depth to allow river traffic to operate year-round. As a result of a dam, there will be two levels of water at the dam site—one level above the dam and a different one below. Locks safely transport boats from one water level to another, like an elevator.
How a Lock Operates
When Approaching the Lock
- Be aware that commercial traffic always has priority over recreational boats.
- Wait at least 400 feet away from the lock for the signal to enter the lock.
- Alert the lock attendant that you wish to go through the lock. You can sound one prolonged blast followed by one short blast of your boat's sound-producing device. You also may contact the lock attendant using your VHF marine radio on Channel 13, but never interrupt commercial communication.
- Enter the lock only after you've been signaled to enter by the lock's traffic lights or by the lock attendant. Otherwise, stay well clear of the lock.
Using a Lock
When using locks, boaters should:
- Have fenders and at least 100 feet of rope to use in securing your boat inside the lock.
- Follow the lock attendant's instructions and proceed slowly.
- Avoid passing another boat when inside the lock, unless directed to do so by the lock attendant.
- Wait for the lock attendant's signal to exit the lock.
Traffic Signals at Locks
Flashing red light means stay well clear of the lock and do not enter. Allow plenty of room for boats to exit the lock.
Flashing amber light means approach the lock at a safe speed and under full control.
Flashing green light means enter the lock.
Animation: Using Locks
Learn more about taking your vessel through a lock with this interactive animation.