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Locking Through

Moving from one TVA-managed reservoir to another by water requires using the navigation lock, or “locking through,” a free service used by thousands of recreational boaters every year. The lock facilities are owned by TVA and operated by the U.S. Army Corps of Engineers.

The locks at Nickajack, Guntersville, Wheeler, Wilson, Pickwick, and Kentucky Dams are open for use by recreational and commercial vessels 24 hours a day, 365 days a year. Call for information about hours of operation at Chickamauga, Fort Loudoun, Melton Hill, and Watts Bar Dams.

It usually takes 45 to 60 minutes to lock through, though it may take longer if there are multiple vessels. Commercial traffic has priority at the locks, but the lock operators try to accomodate recreational boats on every third lockage when traffic is heavy. The lock operator also may wait until several boats are gathered at the lock so that they can lock through together.

Be prepared

All boats going through a lock should be equipped with at least 50 feet of rope or line that can be used to moor the boat to the floating mooring bits (posts) on the lock chamber wall. The floating mooring bits move up and down as the water level in the lock changes. Make sure to put fenders over the side of your boat once you’ve entered the chamber to avoid damage from scraping the lock wall or another boat.

Nearing the lock

Stay in the navigation channel as marked by the buoys. Be aware that some areas near locks and dams are dangerous, and stay clear of those areas. Obey all posted safety regulations and warnings. Learn more about dangerous areas near dams and locks.

Let the lock operator know that you wish to lock through by:

  • Using marine radio channel 16 to identify yourself and your intentions.
  • Using your cell phone to call the lock operator at one of the phone numbers provided on this page.
  • Pulling the small-craft signal cord located in the ladder recess near the end of the upper and lower lock approach walls.

Once notified, the lock operator will tell you how to proceed via radio, phone, or loudspeaker. Be sure to pay attention and obey the traffic signals:

  • A red flashing signal means the lock is not available. It may already be in use.
  • Amber flashing indicates the lock is being made ready. You may approach the lock guide wall, but do not attempt to enter the lock chamber.
  • Green flashing means the lock is ready and you may enter the lock chamber.

In addition to traffic signals, the lock operator will signal with horn blasts. One long blast means enter the lock; one short blast means exit the lock.

For safety reasons, the lock operator has full authority over the movement and placement of vessels in the lock and its approaches. Failure to follow the lock operator’s instructions will not only delay the lockage, it could be very dangerous.

In the lock chamber

Enter the lock at a no-wake speed. Tie off your boat to the floating mooring posts inside the lock chamber with your rope. Do not tie your boat to the ladder or any other fixed point as the water level will change during the lockage. In a crowded lock chamber, you may be asked to tie off to another boat.

Engines should be shut down during the lockage, passengers should remain seated, and everyone aboard should wear a personal flotation device during the lock-through.

Exiting the lock

Remain moored until the lockage is complete, the gate is fully opened, and the lock operator signals you to exit the lock. Exit at a no-wake speed, and do not pass any other exiting vessels until you are well away from the lock.

Virtual lock through

To get a feel for the locking process, you can make a virtual lock-through at the Fort Loudoun lock in Lenoir City, Tenn. The virtual lock through uses a 360 degree camera and QuickTime video to give you a full circle view of the locking process. Complete instructions on controlling the image and navigating through the tour can be found on the left side of the images.

Downstream lock through

Upstream lock through


TVA contact information

Phone Numbers for Locks on the Tennessee River

Fort Loudoun Lock

Melton Hill Lock

Watts Bar Lock

Chickamauga Lock

Nickajack Lock

Guntersville Lock

Wheeler Lock

Wilson Lock

Pickwick Lock

Kentucky Lock

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