Boozy boaters, beware.

The Maryland Natural Resources Police spent the weekend patrolling the state's most-trafficked waterways for drunken boaters in a nationwide policing event, "Operation Dry Water," as they prepare for the throngs that will be out over the coming Fourth of July weekend.


Patrols from the Coast Guard and local agencies joined in the effort, which has been held among police forces nationwide each summer since 2009, Natural Resources Police spokeswoman Candy Thomson said.

A final count of how many were arrested this weekend wasn't available Sunday evening because patrols were out until midnight. Over the last five years, police have averaged about 10 arrests on Operation Dry Water weekend alone, Thomson said.

Last year, a total of 206 people were arrested for boating under the influence, a sharp spike from 124 in 2012, Thomson said.

But police weren't only looking to arrest boaters Sunday, Thomson said. They greeted people, offered to inspect their crafts for proper safety equipment and educated them on the laws of the water, she said.

Generally, the rules — and penalties — for drinking and driving also apply in a boat. Those not driving may drink while on the water, but for skippers over 21, the legal blood-alcohol content level is 0.08 percent.

While many feel safer drinking on the water than on the road, boating under the influence can be more dangerous, Thomson said. The driver of a crashed car can get out and stand on solid land; often, an inebriated skipper in a boat crash is a drowning risk, she said.

Thomson accompanied officers patrolling Middle River near Hart-Miller Island on Sunday. She said excessive drinking wasn't the only risky behavior police came across as they ramped up patrols in advance of the holiday weekend, when many people take to the water for the day or watch the fireworks from their boats at night.

"We saw five people trying to ride one Jet Ski," she said. "Two fell off it, and they were glad when we came to pick them up."

Police were present across the region over the weekend, from Deep Creek Lake in Garrett County to the Severn, South and Magothy rivers in Anne Arundel County. Others patrolled Ocean City's coast line and bays as well as Kent Island on the Eastern Shore. Thomson said the same patrols, if not more, will be on the water this weekend.