Enlarge / These curved timbers, called knees, help support deck beams. (credit: Jim Hansson, Vrak Museum of Wrecks )

Two 17th-century shipwrecks on the bottom of a busy Swedish shipping channel may be the sister ships of the ill-fated Vasa . Archaeologists with Sweden's Vrak—Museum of Wrecks discovered the vessels in a 35-meter-deep channel near Stockholm during a recent survey. Neither wreck is as well-preserved as Vasa (to be fair, there are probably ships actually sailing today that aren't as well-preserved as Vasa ), but they're in remarkably good shape for several centuries on the bottom.

Studying the wrecks could reveal more details about how early naval engineers revised their designs to avoid another disaster like Vasa .

Hiding in plain sight

The wrecks may be the remains of two of the four large warships Sweden's King Gustav II Adolf built in the 1620s and 1630s. The earliest of the four ships, Vasa , had a first trip out of port in 1628 that ended in disaster; the top-heavy vessel caught a gust of wind and leaned over far enough to let water rush in through open gun ports. King Gustav's prized warship sank just a few dozen meters offshore in front of hundreds of spectators.