As you'd expect, island time is alive and well on Grand Cayman. Yet this utterly intoxicated slowed-down version of the ticking clock can thrust you into a temporal paradox as you try to simultaneously chill and scramble to catch the 7:30 boat heading to a distant reef. But so goes a scuba vacation: early to rise, early to dive. And after that second plunge, you can ease back into island time.

Or perhaps not. Take the Sunset House. Founded by divers and

As you'd expect, island time is alive and well on Grand Cayman. Yet this utterly intoxicated slowed-down version of the ticking clock can thrust you into a temporal paradox as you try to simultaneously chill and scramble to catch the 7:30 boat heading to a distant reef. But so goes a scuba vacation: early to rise, early to dive. And after that second plunge, you can ease back into island time.

Or perhaps not. Take the Sunset House. Founded by divers and made for divers, this unpretentious spot on Grand Cayman Island may have found a way to set a diver's watch to island time 24-7. There are the requisite dive boats that jet off the concrete dock like clockwork each a.m. for two-tank dive excursions, and then once more in the early afternoon—a trait of any diving operation worth its salt—boats that are fast and well-equipped, manned by jovial instructors with intimate knowledge of the waters and the reef systems. But the rows of full oxygen tanks sitting next to a concrete wall close to the Caribbean indicate that this ain't your typical dive operation. To put it another way, staying at the Sunset House is like hanging with an eccentric uncle who loves to dive. Simply gear up, find a buddy from one of the dozens of amiable wetsuit-clad divers milling about, and scissor-kick into the sea.

Diving off Sunset House is also far better than you'd expect. Follow the fingers of sand that fan out from the shoreline and you find a healthy coral reef system that slopes down to nearly 80 feet, teeming with sea life, from minuscule baby squid to angel fish the size of a human hand. A mermaid statue sank by the resort stands proudly at 50 feet, eyes pointing toward the glittering sun, one arm out, palm spread, as if in recognition of visiting divers. Fifteen feet away, across a stretch of silvery sand, you'll find the David Nicholson, a small wreck dense with narrow, funnel-shaped coral. Follow the sand chutes further into the deeper blue, and you encounter the Cayman Sea Wall, a forest of coral formations that plunges down hundreds that'll strain the limits of your down time.

The resort is located on the southwestern tip of the island, one mile from the capital city of George Town and Grand Cayman's famed Seven Mile Beach—far enough to dodge the ubiquitous cruise ships (you can see them docked in the harbor from the resort) but close enough to visit when the boats depart. Accommodations vary from courtyard and ocean-view rooms to suites and apartments. The orange exteriors glow a brilliant tangerine at sunset, but the interiors are more utilitarian than Lifestyles of the Rich and Famous, though the cable TV is a nice touch. But that likely won't matter; you'll be spending most of your time here in the water, at the pool, or sitting at the SeaHarvest Restaurant.

And then there's My Bar, easily one of the Caribbean's best thatched-roof watering holes. True to the nature of the resort itself, wetsuits are just as welcome as floral-pattern button-downs, and the food—the same served at the neighboring restaurant—is inspired, from fresh seafood to a special Indian-food night. True to the resort's name, it's also a local's favorite for sundowners.

With all these hearty endorsements, I offer one word of caution: Don't get pulled in too deeply by the island time at cocktail hour. It could make waking for that a.m. boat all the more difficult…

Rates average around U.S.$170 a night, but all-inclusive diving packages are the most cost-effective way to go. The resort also boasts a full-service dive shop, a remarkably good dive photo center, and a variety of seasonal dive special package deals.