HATHEAD: If autumn means birdfeeders and Redskins football to you, the American Wild Bird Co. in Rockville has just the thing -- a Redskins helmet birdfeeder. They can get other teams too, if you dare put a rival helmet up, and all the sunflower seeds you want to fill 'em.

In anticipation of feeding season, the store at 617 Hungerford Dr. also is scheduling September seminars on topics such as attracting bats to your yard, luring woodpeckers and wrens, and selecting proper binoculars. Call 279-0079 for details.

FISH TALK: High Point Marina in Lake Anna plans four striped bass tournaments this fall, the first coming 7 a.m.-4 p.m. Saturday. Cash prizes will be awarded for the biggest stripers; entry fee is $40 per boat. Call (703) 895-5249.

Meantime, Harry Murray at Murray's Fly Shop in Blue Ridge, one of the top smallmouth flyfishermen in the nation, plans two bass fishing seminars this month, one next weekend and another Sept. 29-30. Call (703) 984-4212.

SWEET RIDE: In bicycling circles, a 100-mile, one-day ride is a "century." Next month, Salisbury State University on the Eastern Shore offers one of the easier opportunities for area bikers to complete one.

The Sea Gull Century Oct. 13 follows a flat course down country roads. The route goes from Salisbury to Assateague Island, onto the Boardwalk at Ocean City and back to Salisbury. Shorter rides of 75, 56 and 25 miles are available.

Registration is $12 with a post-ride barbecue for $8.75. For information write SSU Cycling Club, P.O. Box 3046, Salisbury, Md. 21801, or call (301) 543-6012.

RAGS: Twenty-eight entries for the third BOC Challenge 'round-the-world race are filing into Newport, R.I., to prepare for the start of that grueling event Saturday. The singlehanders stop in Cape Town, South Africa; Sydney, and Punta del Este, Uruguay. Philippe Jeantot of France won the first two races and is entered again.

Closer to home, the ninth annual Hospice Cup race is scheduled Saturday off Annapolis, with 75 to 100 entries expected. Proceeds benefit six facilities for the terminally ill in the Washington area.

HOTSPOTS: Chesapeake fishermen in the lower Bay around Point Lookout and Solomons Island report the arrival of schools of Spanish mackerel. The four-pound-and-up macks are mixed with plentiful smaller bluefish, they say, making for a late-season bonanza.

Also, areas around Hooper Straits on the Eastern Shore and Cornfield Harbor at the mouth of the Potomac have been producing flounders up to three and four pounds.

ROOAAR: The fourth annual Chesapeake Challenge powerboat race is Saturday at noon at Sandy Point State Park at the western end of the Chesapeake Bay Bridge, with a rain date Sunday. Organizers expect 50 or more entries in classes 21 feet and up. Spectators can watch from shore, or in areas staked off for boaters on the water. Entry to the park is $5 per car for Marylanders, $6 for out-of-staters.

Anyone interested in racing should call John Wilmoth at (301) 355-3644.

SHOWTIME: Today is the final day of the annual Southern Maryland Wildlife Festival at Charles County Community College off Route 301 in La Plata. Events include wildlife art and craft displays and Southern Maryland-style cooking. Hours are 10 a.m.-6 p.m., tickets are $6. Call (301) 932-5689.