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Locking Through Classes

Attend a free Locking Through program provided in the visitor center theater:

  • Second Wednesday January through March at 7 p.m.
  • Second and fourth Wednesdays April through September  at 7 p.m.

Join us to learn how to successfully transit our locks. Conquer your fears and make locking through an enjoyable experience.

Helpful Information

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Have you ever experienced a near nervous breakdown while going through - or even just anticipating going through - the Chittenden Locks, known locally as the Ballard Locks?

It can be scary, but it needn't be. Just keep your wits about you, follow a few simple guidelines and the next time you transit the locks you will be better prepared, more confident and less stressed.

The locks are located at the entrance to Salmon Bay and the Lake Washington Ship Canal in Seattle. More than 1 million people visit locks each year and if you haven’t been through the locks, a good place to begin is to join the crowd and observe others going through - and ask questions about things you are unsure of.

While you are at the locks, ask for a copy of "Guidelines for Boaters", a handy booklet that outlines what you need to know about locking through. The booklet covers such basics as the equipment required, where to wait, the traffic signals, priorities and the "locking through" process. Keep this handy in your boat, so you can refer to it. It is also very useful to help inform unseasoned guests or crew members.

Another great way to learn is to go through the locks with a fellow boater who has had the experience. You can either go as a deckhand on his or her boat or ask your friend to assist you in bringing your own boat through.

Locking Through: The Basics Preparation

Prepare guests or passengers who are to take part in the mooring. They should be trained in advance of the events to come, before you begin your entry. Give them the "Guidelines for Boaters" booklet to read, plus any special instructions you might have. You'll be too busy during the locking through procedure to wait until then to train them and isn't safe to do so. It can be pretty frustrating for the lock operators to deal with boat crews standing on the bow or stern looking lost and asking what to do. This is especially true when the operators know the skipper has been through before, or that the boat has been sitting outside the locks for some time waiting to come in.

Waiting in Line

As you approach the locks, assume you will be using the Small Lock (to the south). Using traffic signals, tower personnel will tell you if you should come over to the Large Lock. The traffic signals operate like vehicle traffic lights: Red means wait, green means come ahead. If you have a red light or there is traffic ahead of you, it’s best to tie up to the holding pier and wait for either a green light or instructions on the public address system. Do not call on Channel 13, as FCC restrictions prohibit the locks staff from responding to non-commercial vessels unless it is an emergency.

Lock personnel will spot you at the waiting pier and will get to you as soon as possible. If you do have an emergency situation, state so when calling. Your wait will be dependent upon safety and priority. The priority order for vessels waiting to lock through is: government and commercial vessels of all types first, then pleasure craft. Stay alert for a green light. Frequently, the locks crew is standing ready to take boat traffic when boaters aren't paying attention to the traffic lights. Stay aboard your craft while you are awaiting your transit.

Heading In

Entering the locks seems to make people the most nervous. However, this should be easier than tying up at your moorage slip because our trained personnel will give you instructions, take your line and fend you off if needed. Don't let your anxiety put you on edge and set you up for a ruined weekend. The speed limit is 2.5 knots in the Small Lock and three knots in the Large Lock. Take it easy as you come in, but do make sure you are under power. If you are just drifting, you'll have no effective steering control. Stay on your controls until your vessel has come to a stop. Numerous accidents and near accidents occur when the skipper leaves the controls before coming to a stop. Just before you enter the locks, check your reverse gear to make sure it is working and watch for a lock operator to give you hand signals as to which side to tie up on.


You should be prepared with fenders and lines to tie up to either side. The operators will try to accommodate your wishes, but their decision as to which side to put you on is based on safety, staffing and best use of space. It helps for you to repeat the directional signal when you see it, so that the operators know that you have seen it.

Usually in the Large Lock, you will get verbal instructions, as well as hand signals. If you don't understand where it is you are being directed to, ask for clarification. There have been many instances when instructions to a vessel operator weren't understood, so communication can be a problem. It's not unheard of for operators to give instructions for someone to raft alongside a black sailboat on the south side, only to watch the skipper tie up to a white power boat on the north side. We don't mind you asking for a repeat of instructions, but we do tend to get a bit miffed if you end up where we did not want you.

Filling the locks, especially on a busy weekend, is like putting together a giant jigsaw puzzle, with perhaps 100 or more boats in a locking. Operators have to take many factors into consideration including the size and weight of the boats, experience of operators and crew, cleat locations and accessibility, and the total number of boats. Your cooperation in the following directions makes this process go much smoother.

Tying Up

In the Small Lock, hand or toss the middle or end of your line to a lock operator, who will place it around the bollard. After that, secure it to your vessel. Be careful when tossing your line - it's no fun to get hit in the face. In the Small Lock, there are floating tanks that will go up and down with your boat and the water level. During the locking process, keep an eye on your lines just in case the floats hang up, as will happen from time to time. If this does happen to you, slacken your lines, call it to an operator's attention and the flow of water will be stopped.

In the Large Lock, hand an operator the eye of your line and he or she will place that eye on the top of the wall. If you are coming into the ship canal from the Sound (headed east) or are too far away, the operator will throw you a line so you can tie it to the looped end of your line and your line will then be pulled over. Because there are no floats in the Large Lock, you will have to either pay out or take up your line as you go up or down. It is important to pay attention because, unlike with the Small Lock, it takes several minutes to stop the flow of water in the Large Lock. In that amount of time, the water could drop four or five feet. This would either leave you hanging high and dry, or pull the cleats out of your deck.

Lock operators try to stay vigilant to ensure everyone is tending their lines properly, but sometimes there are only two operators available to watch 800 feet of lock wall. When the gates are ready to be opened, you will be asked to secure your lines for safety, as there are strong currents in the locks (as much as six knots). If your lines have been handled properly, they will not have any slack in them when you tie them down.

Casting Off

It is important you never release your lines until instructed to do so by a lock operator. If you are rafted alongside another boat, do not let them cast your lines off until you have been given the okay to go. To your inexperienced eye, it may look safe to go, but the operators often see things that aren't evident to you. When you do cast off, the easiest way for many people to remember which line to take off first is to use this simple rule: saltwater line comes off first. "Saltwater line", in this case, means the line on the west end of the boat; that would be the bow line heading out to the Sound and the stern line when heading into the ship canal. This rule is important because of the direction of the current flow. If you do it the other way around, you might find yourself spinning down the locks, crashing into other boats. That's not a pretty sight and it can be quite embarrassing when you have a large audience.


The lock operator's job is to assist you in getting through the locks as quickly, safely and easily as possible. Bear in mind the emphasis is on safety. Remember, personnel at the locks have to make a lot of assumptions when they are dealing with you. There are more than 75,000 vessels locked through each year and the operators don't always recognize a particular boat. Sometimes, due to noise or poor acoustics, they are not sure if you have heard the instruction - and they may repeat the instructions in an increasingly louder voice. Other times, certain actions are taken and instructions given because the operators are unsure of the skipper's and line handler's capabilities.

If it seems like your boat handling skills are being questioned, don't be offended. The operators are making assumptions on the side of safety. One final recommendation about boating safety in general - It is a good idea to have all hands trained in operating your boat. Take the time to train everyone, so they could respond appropriately if something were to happen to the skipper or a deckhand. Remember the locks personnel are there to help you have a pleasant and safe passage through the locks. Your cooperation and preparation are needed to make it safe and sane.

Basic Equipment List

The following basic equipment aboard your boat will help ensure the safety of passengers, your vessel and others around you:

-       Two 50 foot lines with an eye at least 12 inches in diameter on one end An adequate number of fenders for both sides of your vessel

-       Fire extinguishing equipment

-       One or more personal floatation devices (PFDs) for each person on board

10 Tips for Locking Through

1.     Stay calm and relaxed. This will help out more than anything.

2.     Line up at the waiting piers and wait for a green light or instruction on the public address system. At the locks, Channel 13 is for commercial traffic and emergencies only.

3.     If using the Small Lock, short lines of 15 or 20 feet are sufficient. In the Large Lock, two 50 foot lines, with a loop in one end to give to the lock operator, are required.

4.     Be prepared to tie up on either side, so you don't have to scramble at the last minute.

5.     Have adequate fenders in place to protect your boat, as well as other boats you might tie up to.

6.     Stay alert. Watch and listen for directional signals from the lock operator.

7.     Acknowledge the signals from the lock operator by a hand signal or verbal repetition so that the operators know you clearly understand them.

8.     Come in slowly, but don't drift in. If you're not under power, you won't have good steering control.

9.     For safety's sake, do not untie or cast off your lines unless a lock operator tells you to do so.

10.  When you do get instructions to leave, always cast off the line closest to the salt water first. That would be the bow line first when you are heading west and the stern line when heading east. Article reprinted by permission of Waterfront News


Run through this checklist whenever you use your vessel. These items will help to insure the safety of your vessel and others around you when boating.

  • Two or more 50-foot (15.24-m) manila or other suitable mooring lines. These should be maintained and in good condition (one bow and one stern) and should have an eye at least 12 inches (30.48 cm) in diameter (an eye not made with a slip knot).
  • Fire extinguishing equipment of the type and quantity prescribed by the U.S. Coast Guard.
  • One (or more) Coast Guard-approved Personal Flotation Device (PFD) for each person on board. Children and non-swimmers should wear them at all times.
  • Fenders for both sides of the vessel. Vessels may be asked to moor on either side of the lock chamber or to another vessel.

Your vessel should be in good mechanical condition to insure against the hazards of engine or reverse gear failure, fire, explosion, and sinking. A fire or explosion on a vessel in the lock chamber endangers your vessel's passengers, as well as passengers on other vessels and spectators on the lock wall. Escape from a vessel burning within the confines of the lock chamber could be very difficult.

Traffic Control

To insure a safe flow of traffic in the Ship Canal, the first thing to remember is the speed limit - 7 knots. Watch for areas posted for additional reductions in speed. For example, you must slow to 2-½ knots or less when entering and leaving the Locks.

Also, watch for traffic signals. Red and green traffic signal lights are located in four locations along the canal:

  • The west side of the Ballard Bridge.
  • The east side of the Fremont Bridge.
  • 1,000 feet (304.8 m) west and east of the Montlake Bridge.

Vessels of 300 gross tons (272.15 metric tons) and over, and all vessels with tows, shall not pass the red lights. Vessels of less than 300 gross tons (272.15 metric tons) without tows may disregard these signals but should travel very slowly.

Bridge Raising

If you are in a large vessel or sailboat, you may have to ask for as many as six bridges to be raised. You should know the height of your mast and be prepared to signal the bridge tender at least 100 yards (30.48 m) from the bridge.

    Signal Definitions

        _Short blast (less than one second)

        ____Long blast (les than four seconds)

        _ _ _ _ Four shorts for danger or no opening

        ____ _ _ One long and two shorts to lower salt water barrier in large lock

    Bridge Opening Signals (as encountered from seaward) - All vessels use whistle or horn signals to communicate to bridge tenders

        Burlington Northern Bridge (Burlington Northern Santa Fe Railroad)  ____ _

            Clearance 43 feet (13.11 m) at high tide (mean high water of an approximate 10-foot/3.05-m tide)

        Ballard Bridge (Seattle Department of Transportation) ____ _ 

            Clearance 44 feet (13.72 m) at center span at mean regulated lake level.  Closed weekdays 7 - 9 a.m. and 4 - 6 p.m., except national holidays but closed Columbus Day.  To open bridge 11 p.m. to 7 a.m., call (206) 386-4251, 1 hour before arrival.

        Fremont Bridge (Seattle Department of Transportation) ____ _ 

            Clearance 30 feet (9.14 m) at center span at mean regulated lake level.  Closed weekdays 7 - 9 a.m. and 4 - 6 p.m., except national holidays but closed Columbus Day.  To open bridge 11 p.m. to 7 a.m., call (206) 386-4251, 1 hour before arrival.

        University Bridge (Seattle Department of Transportation) ____ _ 

            Clearance 42 feet 6 inches at center span at mean regulated lake level.   Closed weekdays 7 - 9 a.m. and 4 - 6 p.m., except national holidays but closed Columbus Day.  To open bridge 11 p.m. to 7 a.m., call (206) 386-4251, 1 hour before arrival.

        Montlake Bridge (Washington State Department of Transportation) ____ _ 

            Clearance 46 feet (14.02 m) at center span at mean regulated lake level.   

                May - August, Closed weekdays 7 - 9 a.m. and 3:30 - 6:30 p.m.  September - April, Closed weekdays 7 - 10 a.m. and 3:30 - 7 p.m., except national holidays but closed Columbus Day.  Call (206) 386-4251 (or marine ch.13) 1 hour before arrival. 12:30 - 3:30 a.m. only opens on the hour and half-hour.

        SR 520 Evergreen Point Floating Bridge (Washington State Department of Transportation) ____ _

            Clearance 54 feet (16.46 m) east, 45 feet (13.72 m) west. To open bridge, call (206) 440-4490 a minimum of 2 hours prior to needed opening.  No drawspan openings are allowed on weekdays 5 a.m. to 9 p.m. 

        I-90 Mercer Island Floating Bridge (Washington State Department of Transportation) ____ _

            Bridge does not open. Pass under east and west high rises. Clearance 28 feet east and west of center span. Clearance 70 feet east channel bridge east of Mercer Island.

Traffic lights for the small lock are located on the middle wall when westbound and at the waiting pier near the railroad bridge when heading east. Pay attention to these lights and listen for instructions over the public address system directing you to enter the lock.

When you receive the green light, enter the lock SLOWLY - less than 2.5 knots. You are responsible for leaving no wake. Watch the lock attendant for directions for mooring. Keep the eye of the line on your boat cleat. Pass the loop end of your line to the lock attendant. The attendant will then loop the line around the button and pass it back to you to fasten around your cleat.

Use reverse gear and the stern line to stop. Handle the bow line in the same manner as the stern line. After the gates are closed, the lockage will begin. Be ready to pay out or take up lines should the floating guide walls hang up. (If the floating guide wall does hang when the lock is filling, and you do not pay out your lines, your vessel may be pulled under. If the floating guide wall hangs when the lock is draining, and you to not pay out your lines, your vessel may be tipped.)

Do not secure your line under a knot or with a half hitch - use a Figure-Eight. Once the water has been transferred, hold your lines secured to the cleats while the gates are being opened.

Remember, do not secure your line under a knot or with a half hitch. You must be ready for the unexpected. When the lockage is complete wait for the lock attendant's instructions before releasing your lines. Move ahead SLOWLY- less than 2.5 knots - until clear of the Locks.


Traveling through the large lock is similar to the small lock, but for added safety there are several things to consider.

  • The large lock does not have floating mooring bits to attach to. This requires your crew to tend the lines. As the vessel moves up or down, your crew will have to pay out or take up lines smoothly and steadily with no slack. (Do not secure your lines with a half hitch.)
  • A larger number of vessels can be in the lock at one time. You must be prepared and alert and pay attention to the lock attendant's instructions.
  • Use caution with vessels of different sizes. You will be locking with larger or smaller sized vessels. Larger vessels have much less maneuverability than smaller ones. Smaller vessels can be adversely affected by waves or turbulence.

When heading west in this lock, wait at the upstream timber guide pier, behind the traffic light. When heading east, wait at the waiting pier near the Burlington Northern Railroad Bridge. Watch the traffic lights and listen for instructions over the public address system directing you to enter the lock.

If you draw more than 14 feet (4.27 m), signal the Lockmaster so the saltwater barrier can be lowered. Signal with one long and two short blasts. When the flashing yellow light goes out, the saltwater barrier will be in the lowered position. When you receive the green light, enter the lock SLOWLY- less than 2.5 knots. It is your responsibility to leave no wake that might disrupt another vessel.

Watch the lock attendant for directions for mooring. Pass the loop end of your line to the lock attendant. If the distance is too great, the attendant will throw you the end of a line. Use a slip knot to secure your mooring line to the attendant's line and allow the attendant to pull your line up. The attendant will secure your line to the mooring button on the lock wall. The boater's end of the line should be held by a half figure-eight so that you can pay out or take up line smoothly. Handle your bow line the same as the stern line.

As the chamber is filling or emptying, pay attention to the movement of your vessel and pay out or take up line smoothly and steadily, allowing no slack in the lines. After the chamber has filled, keep your lines secured to the cleats while the gates are being opened. Do not secure your line with a half hitch or under a knot. You may not be able to release it in case of an emergency.

When the lockage is complete, wait for the lock attendant's instructions before releasing the lines. Move ahead SLOWLY- less than 2.5 knots--until clear of the locks. Please use caution and leave no wake that will interfere with other vessels

Paddle boards are not allowed to use the locks.

Kayaks, canoes and other non-motorized vessels are only allowed to use the small locks - stay clear of the large lock waiting piers and traffic channels. Our ability to see you is enhanced if you stay on the South side of the channel. You will be notified by our public address system or by hand signals when it is safe to enter the small lock chamber. Please follow the safety tips below to facilitate your safe passage through the locks.

  • Yield to larger vessels as they will be entering the chamber first for your safety.
  • Do not approach the spillway gates as strong currents and eddys may exist at any time.
  • While waiting for the locks on the downstream side you should wait on the South side of the channel between the small lock waiting pier and the public steps along the shoreline at Commodore Park.
  • While waiting for the locks on the upstream side you should wait on the South side of the channel East of the southern finger pier between the pier and Lockhaven Marina.
  • Please be aware there are many potential hazards in the area and you need to stay alert to boating and water conditions around you.
  • If possible visit the locks to learn what conditions you will encounter when transiting the locks.
  • Attend one of our Locking Through classes.