Archaeologists mapping the Black Sea floor have happily made a surprise discovery—a graveyard of more than 40 ancient ships, Quartz reports. The team, led maritime archaeologist Jon Adams of the University of Southampton, has been studying the historic rise of water levels along the Bulgarian coast. But in the course of conducting research on the seabed with a remote submarine, the team stumbled upon dozens of well-preserved, previously undiscovered shipwrecks. The vessels include ships from the Ottoman and Byzantine empires and could shed light on Black Sea coastal communities going back thousands of years, per a press release,
"The wrecks are a complete bonus, but a fascinating discovery," says Adams. "They are astonishingly preserved due to the anoxic conditions (absence of oxygen) of the Black Sea below (500 feet)." Researchers say that several of the ships are the first-ever discoveries of ship designs that were known from secondhand sources but had never been seen, making them a valuable object of study for historians. The researchers used an advanced form of composite photography to create 3D models of the ships without disturbing the wrecks or the seafloor. (A crew member's hunch led to the .)