Dive Trip: Riviera Maya, Mexico

Course Recommendation: PADI Peak Performance Buoyancy Specialty Course, Pro Dive Mexico Scuba Academy, prodivemex.com

Buoyancy requires maintenance even when it appears to be running smoothly. Each dive-related purchase, be it a wetsuit, BC or camera, alters your ability to stay neutral. It’s also affected the longer you wait between dives, especially if you gain or lose more than a few pounds. Mexico’s warren of caverns, such as Chikin Ha, Casa Cenote, Chac Mool and Dos Ojos, acts like a tuneup, helping you quickly assess buoyancy skills given their tight quarters. “For a lot of people, diving means kicking,” says Angel Navarro, course director for PADI Five Star CDC Pro Dive Mexico. “But do that in a cave, and you can quickly lose all visibility.” Buoyancy is about adjusting your breathing and trim, aka the weight distributed on your body. It’s also a chance to study and refine movements. “You have to move slowly — kick and glide,” Navarro says.

Dive Trip: Monterey, California

Course Recommendation: PADI Dry Suit Diver Specialty Course, Aquarius Dive Shop, aquariusdivers.com

“I taught myself — that’s the hard way,” says instructor Bruce Sawyer of diving dry, a challenge he attempted after logging around 1,000 dives. The owner of PADI Five Star IDC Aquarius Dive Shop in Monterey, California, says that the Dry Suit Diver course is the surest way to stay safe. The greatest danger is triggered by a likely mindless mistake: If your legs are slightly higher than your torso, air can’t escape from the left-arm vent. The suit will invert, tugging you, feet first, to the surface. Regardless of experience level, everyone starts by learning the same skills. “I make them put their nose on the pool floor, feet in the air, and mash down on the inflator,” he says. The challenge is to recover before reaching the surface. Success in the pool is followed by two dives at Monterey’s San Carlos Beach, aka Breakwater. The site’s bottom depth snakes from 20 to 40 feet repeatedly, forcing divers to constantly fine-tune buoyancy.

Dive Trip: Bonaire

Course Recommendation: Project AWARE Fish Identification Specialty Course, Buddy Dive Resort, buddydive.com

“It’s funny when folks dive and say there is nothing to see,” says Augusto Montbrun, dive-operations manager at Bonaire’s PADI Five Star Dive Resort Buddy Dive. Like modern art, a coral reef becomes more fascinating when one understands what he or she is viewing. As part of a promotion two years ago, the dive center included a fish-identification adventure dive — the precursor to the specialty — with every travel package. The freebie inspired many of the resort’s guests to take the full one-and- a-half-day course that focuses on how to distinguish between fish based on their family, shape and environment. “Some of these folks had been coming to Bonaire for years,” Montbrun says. “After they took the ID course, their approach changed. They appreciated all the little things that had always been all around them.” Bonaire provides a laughably ideal classroom for learning to recognize fish of the tropical Western Atlantic: It’s home to seven of the Caribbean’s 10 most diverse sites, including Bari Reef, with a recorded 393 unique species. Learn the fish, then learn to recognize the behavior, and soon you’ll understand the bigger reef picture.

Dive Trip: Cozumel, Mexico

Course Recommendation: PADI Drift Diver Specialty Course, Dive Paradise, diveparadise.com

Before he took the Drift Diver course, Gerard Zingale had 20 years’ experience and 1,300 dives in Cozumel, Mexico. “When I became a divemaster, I wanted to become proficient in all conditions and have an up-to-date skill set,” says the wholesale jeweler. From his time with PADI Five Star IDC Dive Paradise, Zingale knew that currents could rattle a diver, especially those who mostly dive lakes. “I’ve seen folks grab rocks to slow down. They’re not used to the uncontrollability. You have to learn you can’t fight; you just have to go with it.” As for his takeaways, Zingale says the course taught him to be more cognizant of his surroundings, especially the surface. “All the boats transiting the area can be very dangerous. You have to have your safety sausage ready.” He also saw that many of his diving idiosyncrasies needed tweaking. “People have a tendency to drift apart — it’s easy to become complacent,” he says. “When you have considerable experience, you don’t always think about all the details. You really need all your safety procedures in place.”

Dive Trip: Cebu, Philippines

Course Recommendation: PADI Deep Diver Specialty Course, Turtle Bay Dive Resort turtlebaydiveresort.com

You can’t escape: A deep dive is required to graduate to PADI Advanced Open Water Diver, so why not take a specialty course? The trick to handling depth is the same as with alcohol: Be conservative. Nitrogen narcosis muddles your mind just as happy hour does. “We have to show divers that they’re not as bright at depth,” says Chris White, owner of PADI Dive Center Turtle Bay Dive Resort on the Philippine island of Cebu, where reefs lie about 90 feet from shore, dropping steeply to 165 feet. “You need to come up well within your limits.” The Deep Diver course includes several timed tasks that prove to a diver that their reaction times slow, even when they feel unaffected. In other words, it’s impossible to stay within your limits until you know what they are. This specialty is not one that requires any drills. Says White, “It’s in the mind.”

Dive Trip: Grand Cayman

Course Recommendation: PADI Diver Propulsion Vehicle (DPV) Specialty Course, Divetech, divetech.com

Your mind will fire on all cylinders. The Apollo AV-2 Evolution diver propulsion vehicle tops out at 2.6 miles an hour — sounds slow, but it's faster than you'd normally cruise a reef. Whiz past a reef, and it appears that the fish are swimming so slowly, you’ll swear they’ve popped Vicodin. With speed comes responsibility. PADI Five Star Dive Resort Divetech’s instructors emphasize the rule of thirds. Scootering demands that riders eye the battery level constantly. Use no more than one-third of the power to zoom toward your destination, one-third for the return, saving the last third as insurance. This style of diving also requires a heightened awareness of body position, especially if you ride saddle-style rather than gripping it like a sled. If your head is pitched slightly up or down, the scooter and your body will quickly follow. Steering takes a cue from bodysurfing — aim your noggin or an extended arm where you want to go. The best part: Divetech takes trainees to Lighthouse Point, a shore-diving location where they’ve laid underwater lines to mark boundaries and midway points. These ropes guide you right to the wall and back. Instead of worrying about navigation, you can rack up big-animal encounters, explore a wide territory and, most of all, revel in the adrenaline rush.

Dive Trip: Curaçao

Course Recommendation: PADI Night Diver Specialty Course, Ocean Encounters, oceanencounters.com

Sharks, monsters, mermen: In a dark sea, everyone initially fears something. “You lose all the visual cues you’re used to,” says Christian Ambrosi, general manager and course director at PADI Five Star IDC Ocean Encounters, of night diving. Most holiday divers taking a dip in the dark are nervous, and rightly so: Many plunge in only one week a year. Curaçao — with its shallow nearshore reefs at sites such as Shipwreck Point and Director’s Bay — removes many of the pre- dive jitters. The wind dies at night, bringing calm seas. “You’re not worried about miles separating you from your hotel,” he says. “You’re at ease before you get in.” Divers must depower their light for three minutes during the four-dive course. Eerie? Perhaps. Useful? Certainly. You begin to rely on your senses, not your depth gauge, to detect movement in the water column. For Ambrosi, the telltale sign was the water raising or flattening his leg hair. “A small piece of you is learning to dive all over again.”

Dive Trip: St. Croix

Course Recommendation: PADI Shore Diver Distinctive Specialty Course, Cane Bay Dive Shop, canebayscuba.com

“Most people assume shore diving is a slam dunk,” says PADI Instructor Glenn Marshino. “They think they simply swim to a buoy, dive and swim back. Not so.” Cane Bay is St. Croix’s most popular shore dive, but even it poses challenges for the unprepared. Man-made structures alter a wave’s energy flow; in this case, the boat ramp funnels the force back to sea. The shore-diver specialty course teaches divers how to read currents and waves, judge distances, and scout for other potential hazards. Afterward, you’re ready for the island’s more-advanced shore dives, including Willie’s Wish. “You feel like you’re walking over marbles,” Marshino says of the dive’s entry and exit point. The trick, he says, is to get low and turn sideways so the waves strike less of your body. Returning, divers should establish who is the strongest, and let him go in first, then anchor himself on the pebbles to help steady the others. Shore diving, with its waves and hidden obstacles, might fool people in its intensity — but not if you get your hands on the playbook.