The mid-Atlantic coast mackerel watch has started. When the first Boston "mack" arrives is anyone's guess, but with an upswing in temperatures it may be this weekend. Freshwater-bass hounds can score big at Virginia's Lake Anna. The nuclear power station west of Fredericksburg has seen monstrous stringers of largemouths -- all hooked on black jigs with pork-rind trailers.

MARYLAND RIVERS AND LAKES WSSC RESERVOIRS: Slow going thus far, but try a lazily fished jig or spinnerbait around sharply declining landpoints for occasional big bass.

POTOMAC RIVER: It's just about time for white perch around Fletcher's Boat House, off Canal Road; call 244-0461 for the latest details. Rains have raised havoc with the flow and clarity. Be careful. Washington Channel around the Hogate and Flagship restaurants is ripe for crappie. Largemouths are there also, but only the hardest- working will find them now. Relax, there's always the Tidal Basin: It holds crappie, catfish and bass.

EASTERN SHORE PONDS: The spillways of the various ponds are great spots for lazy weekends. Ultra-light spinning gear, small snelled hooks, a few grass shrimp, garden worms, minnows or plain "O" size spinners will draw crappies, bluegills, a few perch, even sizable pickerel now at Tuckahoe and Williston lakes spillway in Caroline County and Wye Mills and Unicorn in Queen Anne's County.

CHOPTANK RIVER: Bass, crappies and a few perch are available during moving tides at Martinak, Greensboro and Denton. A boat is a must. NANTICOKE RIVER: Boaters launching at Sharptown (Rte. 313) head upstream toward Delaware for occasional lunker bass and the almost-always- present crappies in dense underwater obstacles.

CHESAPEAKE BAY: Nothing doing yet.

VIRGINIA RIVERS AND LAKES SHENANDOAH RIVER: High water, little action.

RAPPAHANNOCK RIVER: Still waiting for the white perch. Hickory shad will bloom with the dogwoods.

LAKE BRITTLE: This little beauty near Gainesville will give up some early crappies and sunfish as long as small hooks and worm or minnow baits are used.

BURKE LAKE: A great place for early-season crappie and bass hunters who know the various underwater brush piles in this Fairfax County impoundment. Small Dollfly jigs under a bobber will work as long as the rod tip is gently moved every few seconds. Deep-running crankbaits, bucktail jigs, or spinnerbaits can draw a largemouth.

OCCOQUAN RESERVOIR: It's still early, but a few crappies, sunfish and keeper bass are taking live minnows along brushpiles near deep water.

LAKE GASTON: Deep-running crankbaits can draw landlocked stripers around landpoints in Peahill Creek, Songbird Creek and other lake tributaries. Largemouths have been hard to locate, although this is the state-record lake. Remember it.

LAKE ANNA: Everybody who doesn't mind an early- morning cold nose and stiff fingers has been making the scene at this 9,000-acre nuclear-power supply lake west of Fredericksburg. The reason is simple: trophy largemouth bass, some four-fish stringers totaling over 30 pounds; 8- to 10-pounders -- even one reported 12-pound, 3-ounce bass -- have set the bass-boat crowd out of Sturgeon Creek, Lake Anna and Duke's Creek marinas afire. The lures: all-black rubber-tailed or bucktailed jigs trimmed with black pork chunks or pork lizards. Fish 'em easy and slow over 8- to 10-foot ledges that show deeply dropping water nearby.

KERR RESERVOIR: Downstaters at Clarksville find huge crappies on live minnows or grubs in 10 to 15 feet of water at sunken brushpiles or trees.

ATLANTIC OCEAN OCEAN CITY AND CHINCOTEAGUE: Charter and headboat captains are hop Docks, 301/289-7424. On Chincoteague Island, Don Stiles, 804/336-5433, or in Wachapreague, Ray Parker, 804/787-3341 and Jimmy Wallace, 804/787-3272.