The 20th annual Waterfowl Festival concludes today in Easton, Md. This is the grandfather of waterfowl art shows hereabouts, with some 500 exhibitors, and well worth a look if you've never been.

The show takes over many public buildings in the scenic Eastern Shore town, with headquarters at the Tidewater Inn. Streets ring with recorded goose cries, and the odor of cooking crabs and oysters wafts on the breeze. Show hours are 10-5. Admission is $8. Call (301) 822-4567.


The Potomac River Frostbite Club has begun winter sailing at Washington Sailing Marina just south of National Airport. Races in one-person Lasers are Sundays starting at noon and continue through the winter as long as the river isn't frozen. New recruits welcome. Call Dan Nystrom, (703) 836-2315.


Those who missed Maryland's abbreviated rockfish season last month get a second chance during Virginia's month-long season, which opened Monday. Daily limit is two rockfish a day per person, 18-36 inches long in Chesapeake Bay, 28-36 inches in the ocean. A free permit is required to fish for rock. For information, call 1-800-541-4646.


The U.S. Fish and Wildlife Service, Ruffed Grouse Society and the Forest Service have agreed on measures to boost national woodcock populations, which have declined 36 percent in the East in the last 23 years. Copies of the plan are available from the Woodcock Specialist, Office of Migratory Bird Management, USFWS, Dept. of Interior, MS 630 ARLSQ, Washington, D.C. 20240.


The Maryland Saltwater Sportfisherman's Association is forming a Southern Maryland chapter, its 14th in the state. First meeting is Thursday at VFW Post 2632 on Route 235 in California, Md. Call William Bailey, (301) 475-2313.


The Wild Bird Company in Rockville is organizing a Thanksgiving Wild Turkey Walk with the aim of sneaking up on some actual wild turkeys. The date is Nov. 25, the guide is Tom Valega. Call (301) 279-0079.


Silver Spring's John Swann won the amateur division in the 1990 SuperBass Pro-Am Tournament on Kerr Reservoir in Virginia with a four-day catch of 22 pounds 13 ounces. His prize was a $15,000 bass boat.