In part two of a series on life along eastern Maine's international border, our news team took a look at how agents patrol open water.
Among the ATVs, snowmobiles and trucks border patrol agents use for the Houlton Sector, which covers all of Maine, they also have six maritime patrol vessels.
For the Calais station agents, they said some of those vessels are used to survey close to 2,000 miles, like the area around Eastport and New Brunswick.
Patrol efforts were stepped up following 9/11 but agents said the area has a history of illegal smuggling dating back to early United States history. Border patrol agents said their marine unit staffing hasn't increased much since in the last 15 years.
"It's a lot easier for people to come in through a maritime environment because you don't have all the state and local law enforcement out there and the numbers you do on the land," said Kevin Kellenberger, a supervisory border patrol agent.
The Calais station, which patrols Eastport, has about 25 agents. Three of them protect Maine's border by boat.
They stop people trying to bypass tariffs, smuggling cigarettes and alcohol -- and more recently, narcotics.
Marine agents said in the past few years, they've apprehended about a dozen people crossing the border illegally on the water.
With the islands and peninsulas, there are ways illegal activity can slip through.
"With the water, if we're not there and we don't see them it's kind of open for anybody to come in and out ... because it's such a large area, we only know the ones that we do catch so it's kind of hard to prove a negative," said Kellenberger.
But their duties don't stop at maritime patrol, they also aid in water rescues and car crashes.
"Border patrol way -- jack of all trades," Kellenberger said.
Part of their job is getting back out into the community and making sure commerce takes place the way it's supposed to.
"Since we don't have the resources and we don't have the infrastructure there is elsewhere, we have to work a lot with our community partners. Not only the law enforcement but also just local citizens and business members," said Kellenberger.
Back on land in places like Calais, international business is just a part of daily life.
"Friday nights the Canadians win out every time usually, but most every other time I'm going to say it's 30 percent Canadian, 70 percent Americans," said Tim Crowe, the owner of Jo's Diner & Pizzeria.
Jo's Diner is one of the first businesses you can see from the border checkpoint. The owner said you'll find a steady crowd of Canadians, something that hasn't changed much in the past decade.
Calais locals said they pick up their dry cleaning in Canada, and Canadians come to Maine for other items.
"They come here because the gasoline is a lot cheaper, so they'll come over and fill their cars up," said Shari Doten, the owner of Artemis's Attic.
"It's mostly Fridays and Sundays. You can tell the time when they would go to Bangor on Fridays," said Candy Bridges, owner of Waterfront Boutique.
But the currency exchange rate is a Catch-22 for some businesses.
The American dollar is currently stronger than the Canadian dollar, which paired with taxes Canadians have to pay on goods they bring back means some have lost Canadian business.
"What's good for one is bad for another so it kind of flip flops ... by the time they're done changing that dollar over, even if we have something on sale, it costs them more to take it over," said Bridges.
Throughout the economic ups and downs, border patrol agents in the Calais region said they have a close relationship with Canadian authorities and the areas they serve.
"We can't be everywhere at once. The people who are most familiar with what suspicious is and is not are the people who are there 24/7, and those are our residents and we really rely on them to give us a call," said Mark Phillips, a U.S. Border Patrol agent and public affairs liaison for the Houlton Sector.
"I've done everything from running around in helicopters down south to now up on boats here," said Kellenberger. "It combines my ability to help people ... be part of a solution."