We think we found the drunkest bartender in Manhattan.

The Transom feels confident in this assertion, as we have seen our fair share of Manhattan dive bars since 10th grade.

When we first met Frank Mortagua on a sunny Saturday afternoon he was behind the bar at the Tribeca lushing den Nancy Whiskey. Dressed in his trademark gray tattered Hugo Boss sweatshirt, he had a pair of wire framed sunglasses perched low on the bridge of his nose. He was also pouring a bottle of Budweiser into a small beer glass, another customary trait of Frank the bartender.

“I’m not the boss,” he said, pointing to the “Boss” on his sweatshirt. He then stole a sip of his beer —as he would throughout the day, always leaving a few dollops of beer foam on his Don Quixote-esque mustache.

“He’s either at this side of the bar or the other,” said Bob Cendella, a painter who has immortalized Mr. Mortagua—and Nancy Whiskey’s loyal fanbase of blue collar workers and bohemians— in two murals that hang on the bar’s walls.

Whatever side of the bar he is on, Mr. Mortagua will still be drinking with you.

Frank, 53, was born the son of Portugese immigrants and raised on 6th Avenue and Broome, what he says was once called “The Lower West Side.”

He said he worked just about every kind of job, from a delivery boy for a laundry shop to a motorcycle messenger and a plumber.

“I delivered Bob Dylan his clean clothes,” he boasted.

He said he wasn’t a regular at Nancy Whiskey when the bar first opened in 1967.

“I was underage,” he said, taking our bottle of Amstel Light and tapping it twice on the bar top —as he does with each drink he takes.

He retired from plumbing and eventually co-owned a deli, the Broome Street Food Shop, with his brother, which they later sold in the 1980s.

“I had a couple of dollars, so I didn’t work for a while,” said Frank (he now co-owns an apartment building on Broome Street with his brother).

Frank came to Nancy Whiskey in 1986 after his local, the Rum Runner Bar on Canal Street, shut down.

The pub at the time was filled with a motley mix of roughnecks, lawmen and colorful folk like Frank.

“Nancy Whiskey back then, people were afraid to come here,” said Mr. Cendella.