When Robert Stephenson of Mansfield Street painted a serpentine green monster on a Cressy's Beach boulder 54 years ago, like many public space artists, he didn't advertise his work.
City fathers weren't thrilled about his mark on a piece of pristine Gloucester harborfront.
So when the image was whitewashed out of existence by unknown vandals last week, few knew who had painted the image, or that it wasn't a dragon or a sea serpent, but a depiction of Quetzacoatle, an ancient Aztec deity.
"I painted it at a beach party," Stephenson, now 74, said yesterday afternoon. "We did all kinds of things at the beach back then. It was a much more important place in the 1950s."
Like many public images, the mural had become part of the landscape for generations of visitors, whose appreciation of it grew as decades went by.
And in its disappearance beneath a blot of white paint, the dragon completed a classic circle of public space art such as graffiti and murals: vandalism becomes the vandalized.
But for a certain segment of 1950s beachgoers, the dragon was a symbol not only of Gloucester but another era and community.
"We watched him paint it. I think he just did it on a whim," said Tim Guest, a former Cressy's Beach regular now living in Hilton Head, S.C.
"He drew it on my back in Mercurochrome before he painted it on the boulder," said Sonny Arvilla of Woodward Avenue, referring to an antiseptic. "He was like a guidance counselor to everybody."
Stephenson was the leader of the "beach patrol" at Cressy's, a lifeguard-swimming instructor group at the heart a community of young people who spent much of their summers on the beach.
Back then, Cressy's was sandy, free of the small rocks that cover the surface now, and had its own swimming raft several yards offshore.