I’ve often heard fellow divers say ­jovially that they love scuba diving so much, they’d sleep underwater if they could. But until I discovered Jules’ Undersea Lodge in Key Largo, Florida, I didn’t know it was actually possible, outside a naval ­assignment to a submarine.

The lodge, originally used as an underwater research station in the 1970s off the coast of Puerto Rico, now serves as America’s only underwater hotel. As both a scuba enthusiast and a seeker of all things kitsch and quirky, I was thrilled.

Our topside introduction to the lodge — referred to as a “mission briefing” — had been thorough. We were informed that due to pressure changes, we wouldn’t be able to open our underwater camera housings or pack any toiletries, which were at high risk for subsurface explosions. While the thought of a night without my face cream frightened me in a way some people might fear, say, spending the night trapped in a submerged metal box, I bravely geared up regardless.

After our guide, who introduced ­himself to us only as Wolf Man, took us on scuba through the lagoon and into the lodge, he left us to our own devices.

My dive buddy and I passed the time diving in Emerald Lagoon, ­taking hot freshwater showers (shampoo and conditioner provided), streaming ­marine-conservation documentaries on ­Netflix, playing Oceanopoly (go directly to low tide; do not pass splash), reading through years of rosy messages in the guest book, FaceTiming with family and friends above sea level, and feasting on pizza ­delivered with a howl by Wolf Man.

I sat in the porthole looking for fish while I nibbled on a slice, and came to the conclusion that this was perhaps my most exceptional and memorable ­underwater experience to date. I had fretted that the whole thing would leave me claustrophobic, and wondered how we’d pass an entire 18 hours at 30 feet underwater. But when morning came and it was time to surface, I wasn’t quite ready to say goodbye to the sea.