Friends of V.I. National Park seminars run January through April. Call 779-4940 to make your reservation. Marine ecologist Caroline Rogers of the U.S. Geological Survey takes snorkelers on a Coral Reef Research tour of projects that monitor endangered species of coral. Not recommended for novice snorkelers. The trip runs from 9:30 a.m. to 3 p.m. March 26. Meet at the Caneel Bay Resort dock with lunch, water, snorkel gear, a hat and sunscreen. The fee is $70 for non-members and $60 for members.