If there’s navigable water nearby, chances are you’ll find a historic ship waiting to whistle you aboard. Big or small, these floating icons are lovingly maintained by enthusiasts who live and breathe America’s maritime legacy.

USS Razorback and USS Hoga

North Little Rock, Arkansas

“I know it looks scary,” says Scott Sudduth, coaxing me down the tube-like rear entry hatch. We are in the USS Razorback, a historic World War II submarine that served from Pearl Harbor to Vietnam and is now moored in North Little Rock, Arkansas.

“Don’t worry,” he laughs. “We’ve got Boy Scouts who do this all the time!”

It’s not so much scary down there as just plain dark. The sun outside is high in the sky, glaring off the Arkansas River and rendering everything below invisible. Still, I can just make out the tips of Sudduth’s outstretched fingers below, so down I go.

It’s a short hop to the floor from the ladder’s lowest rung. As my eyes grow accustomed to the low light, I realize I’m rubbing my elbows against a batch of torpedoes. Each of these babies was controlled with a guidance mechanism designed by, of all people, Hollywood actress Hedy Lamarr.

“Razorback used her torpedoes — she sank five Japanese ships,” says Sudduth, whose…