CNN  — 

Explorers will need to go deep to explore the latest trail at Lake Tahoe.

The Emerald Bay Maritime Heritage Trail just opened to scuba divers and snorkelers who want to see Lake Tahoe’s historic recreational watercraft and barges below the surface along Emerald Bay State Park’s shoreline.

Four sites have underwater interpretative panels and waterproof informational cards are now available at the park’s visitor centers, an area dive shop, on the park website (PDF) and on the website of the Sierra State Parks Foundation, which helped pay for the panels and cards.

“This is the first time California State Parks has had an underwater maritime heritage cultural trail open for the public,” said Leslie Hartzell, chief of the cultural resources division, according to CNN affiliate KOVR.

Many boats, launches and barges used in the 1920s and 1930s were likely sunk on purpose in the 1950s when they weren’t useful anymore, and markers explain the history of those vessels.

The barge dive site consists of two barges once used by the lumber companies, which used them to haul wood and transport cars during the summer months. The remaining dive sites are connected to the Emerald Bay Resort, which was a popular vacation destination during the 1920s and 1930s. (The state acquired the land in the 1950s and removed the resort building a campground.

The depths range between 10 and 60 feet.