It pays to be the early bird. Awakened by dawn reaching through the porthole, I peek out blearily at Jackson Bight, a bay of plenty on the north side of Little Cayman. Absolute sheet glass — and no other dive boats in sight. Diving the live-aboard way means always being the first on site. And that can make all the difference.

Twenty-eight steps from cabin to my waiting kit and I’m suited up, prepped for plunge in less time than it normally takes me to crawl out of bed. For breakfast, it’s Nancy’s Cup of Tea — the dive site, not the beverage — just one of nearly two dozen named sites along Bloody Bay Wall, a vertical wonder that plummets 6,000 feet into the Cayman Trough. I follow the guide down over the edge, freefalling past plump yellow tube sponges and delicate sea fans to 100 feet, where I’ll make one of the most fortunate left turns in my scuba diving career.

Moments before, the captain's briefing told us to look for a massive elephant-ear sponge marking the entrance to the swim-through. But even the visual impact of such a robust specimen — something to which you might dedicate a large of chunk time on any other dive — holds no candle to what lies beyond.

The signature feature at Nancy’s is a towering pinnacle that broke off from the wall at some point in history. The resulting fissure hides a host of stunning sights. Wispy black coral trees as big as men thrive inside the protected enclave, along with neon-green sea whips that hang like party streamers frozen midflight. But the real star here is the sun, flooding through the cragged cavern to create a moving theater of light and shadow. The depth makes time short, however, and there’s a lot more to see above.

As I rise back up over the wall, the bright coral garden splayed out ahead holds a treasure trove of marine life in 30 to 40 feet of water: a petite and perfect green sea turtle, a shimmering gold filefish with fluorescent blue markings, schooling blue striped grunts and yellowtail snapper and a juvenile drum flitting in a dance of black-and-white markings. Not to mention lost pirate anchors encrusted in coral and groupers so friendly they’ll swim in for a scratch under the chin.

This scuba diving alone is moving enough to make the trip a success — and it’s only one of 24 I’ll do in a week aboard the Cayman Aggressor IV. As the only live-aboard servicing the rich waters of the Cayman Islands, the 110-foot vessel splits time among the hundreds of world-class dives around Grand Cayman, Little Cayman and Cayman Brac. Completely tricked out to serve divers, the ship offers nine comfortable staterooms with private showers, an easy-to-navigate dive dick with large camera table and an air-conditioned lounge for escaping the elements. Plus I blamed the chef during my voyage for making me extra buoyant with her killer cuisine and decadent apres-dive snacks (not that I'm complaining). And then there's the scuba diving.

Itineraries are flexible, but weather permitting, guests are assured lots of time on Bloody Bay Wall, as well as a visit to the Brac for a dive on the MV Captain Keith Tibbetts — a 330-foot Russian destroyer scuttled in 1996 — plus many of Grand Gayman's best sites.

Access is always key when visiting a dive destination as popular as the Cayman Islands. Choosing to scuba dive via a live-aboard increases your odds of experiencing the finest of the region. And the best part? It’s all right off your back porch. All you have to do is pry yourself out of bed.

Read more in our Ultimate Diver's Guide to Live-Aboards.

Quick Guide
**» _Cayman Aggressor IV
_» 18 passengers, six crew
» Nitrox
» Gear, computer and cameral rental
» Guided tours on request
» Up to five dives per day
» Nearest airport Owen Roberts (GCM)
» Amenities: nine air-conditioned staterooms with private baths; breakfast, buffet lunch, and dinner with tableside service; snacks and complimentary alcoholic and nonalcoholic beverages
» **Contact: aggressor.com