In case you've already tested the waters at the nine beaches on the tour above, here are 11 others to try, all within 1 1/2 hours of the Beltway. (As before, times and prices are through Labor Day, for daytime visitors.) CHESAPEAKE BAY

BAY RIDGE BEACH -- Herndon Avenue, off Bay Ridge Road, Annapolis, Md. 261-2298 (metro) or 301/267-6363. Sandy beach with lifeguards, nettle net, bath house, snack bar, picnic area (bring your own grill). Open 10 to 7 weekdays, 9 to 7:30 weekends. Admission $4.50; $3 for ages 3 to 11.

BREEZY POINT BEACH -- 5230 Breezy Point Road, Chesapeake Beach, Md. 301/257-2561. Half a mile of sandy beach with netted swim area; bath house, shade trees, picnic tables, snack bar (steamed crabs on menu), coffee shop, fishing piers, ship's store, playground, camping, no lifeguards. Open 6 a.m. to 9 p.m. daily. Admission: $3.50; $1.50 11 and under.

ELM'S BEACH -- Bay Forest Road, off Route 234, Leonardtown, Md. 301/475-5621. Unnetted, unguarded beach with changing area (no showers), playing field, grills, picnic tables. Open 11 to 7 weekends and holidays. Closed weekdays. Free admission.

KURTZ PLEASURE BEACH -- Paradise Beach area, off Route 100, Pasadena, Md. (call for directions). 301/255-1280. Unnetted swim area, not much sand, grassy area for sunbathing, bath house, snack bar, lifeguards on weekends only. Open 9 to 7 Tuesday through Sunday; closed Mondays. Admission: weekdays, $2; age 6 to 11, $1. On weekends, $2.50; 6 to 11, $1.50. Over 60, $1 on all days.

MIAMI BEACH PARK -- 4001 Bay Drive, Essex, Md. 301/335-2626. Unnetted beach with bath house, picnic tables, grills, concession stands, lifeguards. Open 10 to 7 daily. Admission $2.50; $1.25 for under 12 and over 60.

PORTERS NEW PARK -- 2201 Rocky Point Road, Essex, Md. 301/686-8769. Sandy, unnetted beach with lifeguards, bath house, picnic tables (bring your own grill), shade trees, concession stand, video games, pool tables. Open 8 to 6:30 daily. Admission $2.50; 10 and under, $1.

ROCKY POINT PARK -- 439 Rocky Point Road, Essex, Md. 301/686-8295. Sandy beach with concession stand, lifeguards, bath house, picnic tables, grills; no nettle nets ("They're no problem here," says a staffer.). Open 6 a.m. to 7 p.m. daily. Admission $2.50; 12 and under and over 60, $1.25. LAKES

CACAPON STATE PARK -- 10 miles south of Berkeley Springs, W. Va., on Route 522. 304/258-1022 or 800/624-8632. A sandy beach on a lake in a 6,000-acre park with golfing, tennis, hiking, picnicking, bath house, snack bar, lifeguards, fishing. Open 10:30 to 6 daily. Admission $2; under 12 $1.25.

TIMBERLAKE -- 11300 Vale Road, Oakton, Va. 620-4000. Primarily for office picnics, the close-to-home, 100-acre complex is also open to the public. It has two 6 1/2-acre lakes, umbrella picnic tables (bring your own grill), snack bar, 4 1/2 miles of hiking trails (with beaver dam, bridges, live bee tree, deer's salt lick), rubber tube, kayak and canoe rentals, fishing. Open 10 to 6 daily. Admission for weekends: $6 adults, $4 children; for weekdays $5 adults, $3 children.

WAYSIDE WONDERLAND -- Route 11, 1/2 mile north of Strasburg, Va. 703/465-5757. A lake at a former limestone quarry on 250 wooded acres with a sandy beach, lifeguards, concession stand, canoeing, fishing, changing area (no showers), lifeguards, picnic tables, grills. Open 10 to 6 Wednesday through Sunday; closed Mondays and Tuesdays. Admission $2.50; 6 to 12, $1.50; under 6, free. POTOMAC RIVER

WESTMORELAND STATE PARK -- Seven miles north of Montross, Va., on Route 3. 804/493-8821. The 1,300-acre wooded park has 1 1/2 miles of sandy beach, picnic shelter, grills, bath house, paddleboat and rowboat rentals, fishing, playground, snack bar, restaurant (steamed crabs on menu), hiking trails, camping. It gets crowded weekends, but no one is turned away, park officials promise. They also say nettles aren't a problem because they don't like these waters. Open 6 a.m. to 10 p.m. daily. Admission $1.50 a car; 75 cents after 3 p.m. on non-holiday weekends.