>> Chicago boating season kicks off today which means it's time to open the gate, invite gate.

We mean the Chicago Harbor Lock which separates the Chicago River from Lake Michigan.

It's right next to Navy Pier.

And it's one of the busiest locks in the nation.

Our patty, what Lee shares, how this feat of engineering it works in our latest edition of Wt Tw explains.

>> Some pretty famous people have been given a symbolic key to the city of Chicago.

And then there's this guy, the Chicago Harbor Lock lock Nestor.

He controls access to the city's real front gate, so to speak.

That gate is the Chicago Life.

A 600 foot long, 80 foot wide chamber that separates the Chicago River from Lake Michigan.

It's the second busiest harbor lock in the nation.

And it's right there next to me deep here.

Everyone was built in the 1930's is part of project that things the Pere first love the Chicago River the whole point of that engineering feat was to keep waste water out of the lake.

But what about other floaters, namely the thousands of boats that travel back and forth between the river and lake every year.

The lack manage is that traffic and not just to avoid gridlock, it's needed because the river is anywhere from one 4 feet lower than the lake.

So I think that the law is an elevator boats in the river, a basically ground level and the law gives them the boost.

They to get to the lake.

Here's how it works.

Boats coming from the river line up in a holding area outside the lock waiting for signals.

A red light means do not enter yellow gives government and commercial boats the okay to move into the lock and green means go for recreational boaters.

As many as 100 boats can feel the lok at one time once everyone's in position that elevator operator likeness or shut the gate behind them to cut off the river.

Next.

The gate to the cracked open lake water slowly fills the lack of votes ride with the rising level.

>> Once the lock is even with the lake, the gates open wide and boats exit into the open water.

>> The steps to reverse for folks returning to the river from the lake.

They had the Watergate are back down to a different level.

The whole process takes about 10 to 15 minutes and it's repeated more than 10,000 times, every boating season, another hardworking feat of