Diving in the Hawaiian Islands
When molten lava meets the cooling waters of the Pacific, things can get violent. Volcanic flows are frozen into domes, pillars and finger-like ridges, while conduits of liquid rock empty to become cave-like lava tubes. This is how volcanic islands form, and evidence of the Hawaiian Island's fiery rise from the depths can be seen along the coastlines. Older islands such as Kauai and Oahu have the luxury of time to cultivate more extensive coral barriers, while younger Lanai and the still-building Big Island are surrounded by sharp relief formations that offer swim-throughs, grottoes and arches. Water conditions are not favorable to soft coral growth, but hard corals thrive from the surface to depths well below 100 feet. Surf zones and shallows are often dominated by cauliflower, lace and antler corals. Larger lobe corals take over as depths increase, and are also joined by the more fragile finger corals. Acommon sighting on reefs are the peacock grouper that hover at cleaning stations, and the moray eels that peer out from cover. Squirrelfish and blackbar soldierfish hide beneath ledges, and sand valleys between coral heads are alive with garden eels and peacock flounder. As depths increase, schools of bicolor and longfin anthias join the show, and there's usually a chance to find white tip sharks nosing into crevices in search of a meal. There is always a chance to catch a glimpse of larger sharks such as hammerheads, tigers and gray reefs passing by in the distance, but far better odds of running into sea turtles or the pods of spinner dolphins that frequent calm bays. One of the most dramatic big animal encounters takes place at night on the Kona Coast, when manta rays gather to feed on tiny creatures revealed by the glow of a hotel pier's underwater lighting. The cave-like formations known as lava tubes are diver favorites, and two of the most famous are found on the shores of Lanai. Cathedrals One and Two are submerged tunnels with chambers more than two stories high, with perforated ceilings that usher in radiant beams of sunlight. Another unique lava tube is Maui's Bubble Cave, which begins in shallow water, and leads to a partially air-filled chamber that seems to breath with the rising and falling swell. More common are the dome-shaped lava formations the size of houses, and the numerous arches formed by the erosion of lava pillars. At sites such as Turtle Town, divers can pause to watch the show as green turtles come in for a cleaning, with yellow tangs, damsels and wrasses flitting about as they pick parasites from shells and flippers. Near-shore ledges such as Black Rock and Five Caves provide lively night dives. Diver's lights reveal prowling invertebrates. Lobster and crabs scurry about while octopus and eels slither stealthily through the shadows. A less-expected night dive takes place offshore of Kona, where divers tethered below the boat drift in darkness, using their dive lights to spot enigmatic nocturnal creature that rise from the depths. Oahu offers the best collection of wrecks, which includes three substantial vessels—the YO-357, Sand Tiger and Mahi—plus several smaller boats and a number of ditched aircraft. Maui is the starting point for dives to Molokini Crater and the caverns and canyons of south Molokai. The coral channels of Kauai's north shore reefs are best dove in calmer summer months, and this is also the season for day trips to remote Niihau island for gigantic sea arches, big fish and perhaps a swim with monk seals. Kona offers the broadest range of diving adventures, from calm, coral-studded bays to caverns and deep drop offs, with most sites less than a mile from shore, and in the calmest water in Hawaii.