A navy-trained dolphin made a rare discovery in California recently following a routine mine-training exercise. A bottlenose dolphin reportedly uncovered a 130-year-old, self-propelled Howell torpedo off the coast of San Diego.

The 11-foot relic was discovered by a U.S. Navy Marine Mammal Program dolphin named Ten in March nearby the Hotel del Coronado, with another dolphin, Spetz, confirming the find one week later, according to Grind TV. The located torpedo was one of only 50 ever created and one of two ever recovered, reportedly originating from the 19th century.

“A diver went down and began to sweep the dust and debris off, and they realized that they had found something significant,” Christian Harris, operations manager for the program, told the San Diego Union-Tribune, confirming that the water mammal uncovered and marked the location until divers could investigate.

Officials are uncertain as to how San Diego was the torpedo’s final resting place but are guessing the weapon, whose warhead feature was missing, originated from an aerial drop mine.

Operations Manager with the Navy Marine Mammal Program Braden Duryee said, although it is common for the trained dolphins to make underwater discoveries during their sea mine detection searches, the particular find was noteworthy.

“We find things all the time. [The dolphins] are very good at finding things, and we find some 'off' things, but it was just one of those days where the animals found it. It was kind of in our way,” Duryee said. “Realizing that we were the first people to touch it or be around it in over 125 years was really exciting,” he said.

The torpedo is reportedly being kept in a tank of water to prevent corrosion and is planned to be shipped to the Naval History and Heritage Command at the Washington Navy Yard in Washington, D.C. According to Grind TV, the first historical Howell torpedo discovered is currently on display in Keyport, Wash., at the Naval Undersea Museum.