Submersible pilot Chuck Holloway shows fifth-graders from Le Jardin Academy at Sand Island today the exterior of one of the deep-sea vessels used on a 64-day voyage to the Northwestern Hawaiian Islands. Gregory Yamamoto • The Honolulu Advertiser

A video captured a close encounter between the research submersible and a monk seal at the 1,500-feet depth. Woods Hole Oceanographic Institution

The researchers just returned from a 64-day voyage in the Northwestern Hawaiian Islands conducted by the National Oceanic and Atmospheric Administration with support from the Hawaii Undersea Research Laboratory, its deep-sea submersibles Pisces IV and V, a remotely operated vehicle and a seafloor mapping sonar system. They traveled aboard the University of Hawai'i’s research vessel Ka'imikai-o-Kanaloa (which means "heavenly searcher of the seas).

Amy Baco-Taylor of Woods Hole Oceanographic Institution said the team was studying reproductive biology and genetics of deep-sea precious corals. "We made exciting discoveries, including four new coral beds, gold corals found spawning in the sample jars on the surface" and some young coral trees that they hadn’t observed before.

Terry Kerby, submersible pilot and operations director, said the voyage was full of discovery but the most exciting moment probably came when a monk seal encountered the vessel 1,500 feet deep. Although researchers know the marine mammals can go to great depths, it was unusual to see, he said. "The monk seal swam up and looked in."

Students in grades three to seven came from four O'ahu schools to the Sand Island pier to learn more from the team just back from a voyage of discovery. The schools are Kalakaua Middle School, Le Jardin Academy, Moanalua Middle School and Sunset Beach Elementary School.

Moanalua Middle School seventh-grader Xaviera Quintero said she thought today’s field trip was better than most because the topic was interesting, the researchers explained their issues well and they gave out some good "free stuff."

The educational goodies included "Explore" pens, rulers, a pin, brochures and information sheets, and some postcards with photos taken far below the ocean’s surface.

Quintero also was amazed by the story of a 32-foot-long whale shark and "how it was so friendly" to the exploring team, and stayed with them for 45 minutes.

Le Jardin fifth-grader Tyler Cundiff couldn’t get over the modern techniques for scientific discovery and the fact that the submersible can take teams 6,500 feet deep. "I can only go down about 10 feet and then my ears start popping!" he said.

Cundiff also asked the explorers what would happen if water penetrated the vessel. Pilot Chuck Holloway assured students the vessels have safety features that would help them return to the surface even if mechanical and electrical problems trip up some of their technology.