The Lock Between River and Lake on a Chicago Night Cruise

What happens between the gates

The lock sits at the mouth of the river, where it meets the lake. The chamber is 600 feet long and 80 feet wide, and it can hold up to 100 vessels at once. It has two pairs of sector gates, each 30 feet tall.

The river and the lake usually sit at slightly different levels, typically two to five feet apart. Your boat enters, the gates behind it close, and the gates in front open partly so that the water levels out by gravity. When the two sides match, the gates open and you sail through. A typical cycle takes 12 to 15 minutes, and a guide uses it to explain how the lock works.

It is calm inside. You stay in your seat, and most people spend the time taking photographs back along the river. What else to expect on the night is on what to expect.

What you see on the far side

When the lake gates open, the view changes all at once. Behind you is the river among the towers; in front of you is open water. On the night cruise, the guide points out Navy Pier and the harbor lighthouse, then the boat turns so you can see the whole skyline lit from end to end. That view is the reason to choose a cruise that uses the lock.

You come back the same way. The boat returns through the lock to the river before it heads for the dock, so you go through the gates twice. Allow for both when you work out when you will be back on land.

Why the lock is there

The lock was built between 1936 and 1938 by the Sanitary District of Chicago. Its main job was to limit how much water flows from Lake Michigan into the river. It was also part of the project that reversed the flow of the Chicago River, to improve the water quality of the lake.

Since 1984 the U.S. Army Corps of Engineers has run and maintained the lock. Sluice gates beside it still let lake water into the river, and in a very heavy storm can let the swollen river out into the lake.

Which evening cruises go through, and which stay on the river

This is the question that decides your view. A cruise that uses the lock gives you the whole skyline from the lake; one that stays on the river gives you the towers from below.

The night cruise from Michigan and Wacker and the sunset cruise from 400 N Michigan both pass through to the lake. First Lady's Creepy Cruise does not use the lock, and neither does the twilight tales cruise, which is the same storytelling evening on the river sold under a second title. If the lake is the point of your evening, check that word, "lake", is in the name of what you book. The whole choice is laid out on the night tour options page.

The wait on a busy evening

The lock takes boats in turns, and on a busy night there is a queue. Most evenings the wait is short. But on holiday weekends and warm summer nights it can run long, and travellers have described it plainly. One spent much of a night cruise waiting for the gates to open onto the lake. Another, on an August sunset sailing, sat in the queue for almost an hour and never reached the lake at all. A third found the lock closed at first, so the boat toured the river and made up the time on the lake afterwards.

The route on the sunset sailing depends on the lock, the weather and the captain. If you are worried, ask the crew when you board how busy the lock is that evening. A long wait can eat into your time on the lake and push your return later.

If you want the lake without the queue

• Avoid holiday weekends. They are when travellers describe the longest waits.
• Go outside high summer. From September the evening sailings are dark sooner, so the lake view is lit even on an early departure.
• Or skip the lake. The river cruises avoid the lock altogether and give you the towers lit from below.
• Or see it from above. The skyline flight takes about seven minutes and never waits for a gate.

Questions you might have

• Do you get off the boat? No. You stay aboard, on deck or in the salon, the whole time.
• Is it rough? No. The water inside the chamber is calm; the chop comes later, out on the lake.
• How much time does it add? About 12 to 15 minutes each way, plus any wait for your turn.
• Can you see it on the river-only cruises? Not from inside. Those evenings turn before they reach it.

Both cruise docks, a block apart on opposite banks, are on the meeting-point map. The landmarks you see once you are out on the lake are on Chicago Night attractions, and what to wear on the water explains why the lake side is colder.

Evenings through the lock, and one that stays on the river

Chicago By Night River and Lake Cruise

First Lady's river and lake cruise after dark: 90 minutes with a live guide from the dock at Michigan and Wacker, up to 250 aboard, with an enclosed salon below the open deck.

From $50 per person

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Lake Michigan Sunset Cruise in Chicago

Ninety minutes from 400 N Michigan, timed to the sunset: the river first, then the lake as the lights come on. Light narration from the crew, not a guide; the bar takes cards only.

From $45 per person

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Chicago: Historic Gangsters & Twilight Tales Night Cruise

Ninety minutes of gangster history and twilight tales on the river after dark, from the First Lady dock. A live storyteller, a bar on board, and river only.

From $46 per person

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