Transcript for Underwater treasure holds clues to American history

A giant hidden treasure lies just beneath the water outside the nation's caps it's a collection of abandoned ship's hold includes two American history. Here's ABC's Serena Marshall. On this peaceful strike to live at home and just thirty miles from hostile and Washington DC who lies the largest ship graveyard in the Western Hemisphere. This is malice day. Home to more than 180 vessels decaying in the shallow waters some more than three centuries old and many of them would in steam ships from the first. World war. The boats were built it really quickly in a span of two years as a massive national push. To build this fleet of ships and World War I. But by the time they completed in the war was over. And so the tips were sold and eventually scrapped. Obsolete they were burned in 1925 and left here creating the ghost fleet and hallows day. When the tide goes down the ships lurking beneath the surface rise and there it out to fully appreciate the splendor kayaking out we explore the racks and many now covered nature swallowing the remains. I'm for us bikinis to light at certain. A guy and look appears to be Italy and Madonna had to vote that Syria and their chefs shipwreck Fiat. There's a shipwreck right there right there yeah right there. And as you get up close. You'll be able to see the old locals of the ship have become. While. The ghostly only comes out a little time and when it does come now you can get up close and personal and types who bled and metal that made up these or one cent. It's like some incident in the land but it's been deal. This ghost fleet growing into of the wildlife sanctuary. And what remains now home to thriving populations of birds fish oysters and crab. The testing that has them very muddy bottom and there's very little structure for. Plants and animals to latch onto niches or preachers took to drive them. And these ships have given that structure. Within this day the day. Under consideration to become a national marine sanctuary. If approved by the government it'd be the first and more than two decades. One of the largest and most recent ships aftermath. A one time fairy made obsolete by new technology. Left like the others with a new purpose from cutting through the scene to reinvigorate and tuck school. And Marshall ABC news malice bay in Maryland's. Critical that they remain there all this time have to build them. Quick they've built on cheap but still low cost snuff the war ended. And then there are yet to the very fear that were completed in time most of them have leaks in the anyway so the consent in the hot and people like Serena kayaking around having a lovely time.

This transcript has been automatically generated and may not be 100% accurate.