A man aboard a barge exchanges gunfire with police. Seconds later, SWAT team members shoot the man and seize control of the boat.
Thankfully, it's only practice -- just in case it really happens.
"A lot of these scenarios are set up where there's no right way to do it, or they're two or three ways that they can accomplish the mission successful," said David Block, a member of the U.S. Coast Guard.
It's the first time the local SWAT teams have executed missions on the water. In this Diamond Defense Exercise, they're getting in-depth training related to boarding, searching and securing the river.
It's a course given by members of the Coast Guard.
"You just have to be ready. You never know what situation is going to pop up and you just want your teams ready and familiar with it," Block said.
While no one can foresee anything happening on the water, members of the Coast Guard hope practice makes perfect for the real thing.
"I think doing this puts the public at ease that we're doing what they're paying us to do," Block said.