Buying some weed and heading to the beach may sound like an enjoyable way to spend a Saturday. But if that's how you're planning to spend your weekend, make sure you keep an eye out for the U.S. Coast Guard, because they will arrest you.

A news station in Maine recently reported a story about the U.S. Coast Guard enforcing marijuana laws in America's waterways. The Coast Guard says it's their duty to enforce federal laws in American waters, and since cannabis is illegal under federal laws, they will arrest people for possession of marijuana even if they're in states where it's legal. 

Perhaps the most disturbing part about the Coast Guard's policy is it doesn't just include commercial boats out in the waters, but also passengers. People can take ferries from Portland to nearby islands in Maine, and the Coast Guard says that they can arrest people on those trips if they're in possession of marijuana. 

"From time to time we are on the Casco Bay ferries and we’ll ride those to Peaks Island and back for officer presence purposes," says Lieutenant Jeff Bryant of the Coast Guard.

This story comes out just a week after U.S. Attorney General Jeff Sessions asked Congress to allow the Department of Justice to enforce federal marijuana laws in states where cannabis is legal. While the Senate turned Sessions down, apparently those restrictions don't affect the Coast Guard.

Bryant says that enforcement of marijuana laws isn't necessarily a priority for the Coast Guard, but they cannot selectively choose which laws they follow while on the job.

“Our primary purpose out on the waterways is for the safety and security of the boating public. We can’t pick and choose which federal laws we enforce and marijuana remains illegal under federal law so if we do come across it we will enforce it”, Bryant says.

So for now, make sure to only use marijuana while planted on solid ground.