SAV'S: The federal Chesapeake Bay Program announced that submerged aquatic vegetation declined in the bay last year after a decade of steady increases. Bay grasses were down 8 percent from 1997, mostly because of a steep decline in Tangier Sound, where acreage has dropped 30 percent in the past year, 63 percent since 1992 and 99 percent since 1952. The news was better in the Potomac, where grasses were up 20 percent, and in the upper Chesapeake, where they were up 3 percent with notable increases in the Severn, Magothy and South rivers. Submerged bay grasses are considered key indicators of a healthy waterway; they replenish oxygen, stabilize the bottom and provide habitat for little fish.

HAPPY TRAILS: The first hike on the newly named Fairfax Cross-Country Trail is slated Saturday, with a follow-up on Sunday. The 35-mile route from Lorton to Great Falls is the longest natural surface trail in Fairfax County. Hikes start at 8 a.m. both days. Call 703-821-0975 or 703-534-5251.

ALL IN THE FAMILY: Virginia's Department of Game and Inland Fisheries hosts a family outdoors weekend next weekend at Holiday Lake 4-H Center in Appomattox, Va. The session is designed for families with youngsters 9 or older and includes instruction in archery, canoeing, shotgun, fishing, wildlife and camping. Cost of $65 includes meals and lodging. Call 804-367-6351.

LUNKER: The Lyceum, Alexandria's history museum, sponsors a "biggest fish in the river" tournament Saturday, the first day of National Fishing Week. Prizes will be awarded for largest catfish, crappie, smallmouth and largemouth bass and rockfish. Registration is $5 a person with headquarters at Jones Point Park. Call 703-838-4994.

ONLY THE BEST: Some of the top women sailboat racers in the world come to Annapolis this week for the Santa Maria Cup, the oldest women's match-racing series in the nation. Among 12 women vying in J-22s from Wednesday to Sunday will be America's Cup skipper Dawn Riley of San Francisco, five-time yachtswoman of the year Betsy Alison of Newport, R.I., and Paula Lewin of Bermuda, the world's top-ranked women's match racer. Headquarters is Eastport Yacht Club; call 410-263-0415.