Behind the scenes at Canada's largest port

A horn blaresas a small tug boat guides a large container ship leaving the port from downtown Vancouver towards the open sea.It's a common sight, as are the boats waiting just outside Vancouver's harbour in English Bay.

The Port of Vancouver is the largest in Canada, making it an important nexus for trade and the country's economy.

But despite the heavy marine traffic and its enviable location in the downtown core, the port is often separated from the city it's a part of.Increased security after 9/11 meansaccess to the port is tightly controlled.

CBC got an insider's view of the action.

A busy port

It might look quiet from the distance, but up close the port is usually humming with activity.

The porthandled 138 milliontonnesof cargo in 2015, valued at $200 billion.And with 27 marine cargo terminals shipping a diverse portfolio from automobiles to grain and containers, the traffic going in and out can be quite hectic.

The port is also home to many marine animals, like these seals that like to sunbathe near the docks.

The port authority

For Kevin Ball, it's the smaller boats that are usually more concerning.

"Especially in the summertime, you've got all the pleasure boaters out who are not aware of the rules of the road," the senior harbour patrol officer said.

"Sometimes you see them heading towards one of the larger ships, and the captain can't see past those giant containers. You think he should be able to see you, but it's much further than you think."

Balland other harbour patrol officersare out on the waters almost 24/7, scouring for anything that looks out of place.

Traffic control

The port authority manages over 16,000 hectares of water,more than 1,000 hectares of land and approximately 350 kilometres of shoreline.

To manage all of that, the port has almost 400 cameras the operations centre can tap into.

It also monitors by GPS the location, speed and wait times of every truck and ship over350 tonnes.

Andriy Tereshchenko, one of the operations coordinators,says the ship traffic can also produce some interesting challenges.

"Sometimes there can be an interestingcalculationthat you have to make when you have a large vessel coming under the Lions Gate Bridge, and you have to see if it has enough clearance, figure out when the tide is right."

All ships coming in and out of Burrard Inlet are piloted by a B.C.-trained coast pilot all the way to when the ships move past Victoria.

"They are specifically trained for these waters," Ball says.