Watching marine life up close, in the dark By Katherine Nichols / September 29, 2003 Share 1 -- KAILUA-KONA, Hawaii -- The current moves as manta rays with 10- or 12-foot wing spans sail by, so closely I have to duck. It's spectacular. Watching such majestic animals in their environment evokes powerful emotions. Even after diving at many wonderful destinations, watching mantas in their graceful dance for blooming plankton stands out as a highlight of my underwater experiences.In fact, the Big Island is one of the few places in the world where divers can see giant manta rays up close in water as shallow as 20 feet.Eco-Adventures, a 12-year-old company based on the Big Island, specializes in manta ray night dives. The two-tank twilight/night dive begins with a check-in at about 4 p.m. (times fluctuate depending on the sunset) and a relatively shallow (up to 50 feet) first dive to examine the changes in the marine life just before it gets dark, said Amanda Steenman, an instructor with Eco-Adventures.Divers exit the water in time to refuel with snacks and nonalcoholic beverages and watch the sunset from the company's 50-foot catamaran.The boat is certified for 98 passengers, but Steenman said they keep the number of divers aboard to fewer than 20 so there's ample room to move around.Between dives, the crew will change tanks for you. Indeed, handling gear is a nonissue. Crew members load equipment on the boat, set it up, break it down and rinse it afterward.For those traveling without their own regulator, light and buoyancy control device, Eco rents each item for $5, meaning divers can outfit themselves completely for less than $20.After participating in the first, predarkness dive, I listened to what Steenman described as "a great, very thorough marine briefing."An instructor explained the mantas' behavior and diving etiquette.Microscopic organisms called plankton are attracted to light; mantas eat plankton by swimming through masses of it with their mouths wide open.Touching the mantas at any time was forbidden, as was scaring them with a quick exit or ascent (which no sensible diver would do anyway).During this time, instructors also answered questions participants might have about the first dive and the marine life they saw -- in our case, a shark sleeping in a cave.The catamaran then traveled to the best location to view the mantas. When darkness fell, the scuba divers jumped in -- carrying more weight on their belts than usual -- and sank to the bottom shrouded in black.As we were told before entering the water, we directed our lights toward the surface. And waited. Gradually, plankton became more visible. Then the mantas began to arrive. We saw only two swimming in graceful, roller-coaster-like circles around each other, but that was plenty.Night diving is not for everyone. The feeling of weightlessness combined with absolute darkness was more than a little disconcerting -- especially when your goal is to attract animals much larger than yourself. But as Steenman said, "This is probably one of the easiest night dives you can do."That's because this is not a blue-water (very deep) dive, and guests are not disappearing by twos into the abyss. Everyone sticks together.And with all of the lights shining, there are moments when it doesn't feel like a night dive at all.Steenman said beginners are welcome as long as they feel comfortable in the water. Each instructor handles no more than six participants.Even snorkelers are welcome to participate in these dives, as the mantas can sometimes swim within inches of the surface. The vantage point is different, and you don't need to be a certified scuba diver to enjoy the adventure.The twilight/night manta ray two-tank dive costs $102 per person. Snorkel dives are $65, including gear.Travel agents earn 10% commission; group commission varies.Hotel/car/dive packages are available on the company's Web site at www.ecodive.com.There also are three-tank, all-day charters; wall dives; morning and evening charters; and blue-water excursions.Advanced divers can enroll in Nitrox, Trimix or rebreather courses as part of a trip package.For additional information, call (800) 949-3483.To contact reporter Katherine Nichols, send e-mail to email@example.com.