Some of the military's most advanced ships are docked in the Philadelphia region this weekend as the U.S. Navy and Marine Corps celebrate 250 years of service. The USS Billings is among the ships now open for free public tours.

The USS Billings is a littoral combat ship that was built for speed, maneuverability and coastal operations. It's moored next to the iconic Battleship New Jersey in Camden, offering visitors a striking contrast between the Navy's past and present.

"I heard about the Billings," George Chitty of Bricktown, New Jersey, said. "They said it was a newer ship. So I've never seen anything like that."

U.S. Navy Lt. Commander Michael Murphy, the ship's operations officer, said the Billings crew is proud to take part in the historic celebration.

"For the USS Billings to not only be part of this, but also to be alongside an amazing battleship like USS New Jersey, is a one-in-a-lifetime experience," Murphy said.

The ship's advanced features are drawing plenty of attention, including the MK 110, a 57mm gun that can target both air and surface threats.

"It's super historic and I wouldn't miss it for the world," John Gourley from Newark, Delaware, said. "It was the beginning of a great American experiment, which continues today, and hopefully for the next 250 years."

Four Navy ships in total are open to the public through the weekend in both Camden and Philadelphia. Guided tours include opportunities to meet the Sailors, learn about life aboard ship and understand the Navy's evolving mission.

"Every tour I go to, the people that you meet and surround yourself with, everything is a learning experience," Murphy said, "and you kind of just go in with a growth mindset."

This weekend's celebration not only honors 250 years of sea service but also aims to inspire the next generation of service members.