NAPA (CBS SF) — A wayward porpoise¬†was spotted cruising in the Napa River near a boat dock Thursday morning.

Mary Dwyer heard about the sighting, and packed up the car to go see it herself.

“This is free, folks! Why go pay money for wine?” Mary said.

Josh and Jennifer Thye were lucky enough to be holding a camera when the porpoise surfaced.

“We’re from Phoenix. ¬†We don’t see dolphins in Phoenix, so I thought it was kind of cool,” Jennifer said.

Marine biologists say it’s not actually a dolphin, but a harbor porpoise, one of the smallest marine mammals.

“We were caught off guard trying to see how it made its way this far in,” Josh Thye said.

The sighting was a rare occurrence for the tourists.

“You don’t come to Napa to see dolphins, so it’s kind of neat.”

Porpoises have shown up in the Napa River in the past, and the river contains salt water, so it is believed the porpoise was not in trouble.