Boats were close, kinda. The guess was only off by a few thousand fathoms.

"Worked with bathyspheres, a high rise or two. Never really seen a boat, or car."

He'd seen a train though. More than once. He'd even ridden it by himself! Sadly, none of the cars he'd seen around seemed very similar to trains. He hadn't fully examined any, but the ones in the parking lot were markedly different. He wasn't quite sure how they worked - they didn't even have rails, which was a dangerous and foolhardy design choice. Someone could really hurt themselves!