If you were in the Best Products store in New Carrollton last week and saw a guy wandering around the sporting goods department tearing at his thinning hair and saying, "Somebody please stop me," that was me.

The day before Mike Sullivan, who runs the charter boat Miss Dolly out of Chesapeake Beach, had called to report that four huge striped bass were caught by some fisherman trolling at the mouth of the Potomac.

"I'm ready for 'em," said Sullivan. "How about you?"

The painful truth is that I couldn't have been less ready. All winter I'd put off the purchase of trolling equipment, knowing full well that when the first fish was captured I'd kick myself for waiting around.

They don't have carts at Best Products, but after about the third trip to the cash register the hired help started coming along with me to help tote the goods to the checkout. We were loaded down and trucking.

Five Tony Accetta No. 19 and 21 spoons; 1,600 yards of 30-pound-test monofilament and 500 yards of 50-pound line; seven bucktails in size 6/0 and 7/0; six rubber surgical hose eel-type lures; two Daiwa trolling rods with roller tips; two Penn 111H 2/0 trolling reels; a box of snap swivels and a box of barrel swivels; lead in-line sinkers of 3, 4, 6, 8, 10, 16, 20 and 28 ounces (at 10 cents an ounce); three jars of Uncle Josh split-tail striper pork rinds; and a package of Mann's Sting-Ray grubs marked down from $1.17 to 37 cents. Thank heaven they were out of single-strand wire line, or I'd be paying overdraft fees.

I wrote a check, having made that morning a fat deposit to cover the mortgage and the Visa bill. The Best check left the balance at $2.61. The mortgage would just have to wait. ;

If this sounds like a case of angler in extremis, so be it. The simple fact is that trolling, for all the initial expense, is the No. 1 fishing technique on the middle bay. There is no other way to consistently catch fish and only one way to do it right -- with the right equipment.

"We always thought we were doing it right," said Sullivan, "until old Walter Booker showed up at the dock one spring with his boat, 'My Desire.' We were catching maybe two or three rockfish a day. He started coming with eight or nine.

"We watched him for awhile and finally one day I couldn't stand it any more. I went over and told him. You're making the rest of us look bad. I don't expect you to tell me all of it, but just lead me part of the way.'"

Walter Booker gave a little lesson and since then the trollers in the middle Bay have all followed the same technique and used the same equipment.

Their season is starting now, although the official beginning isn't until May 1. The biggest striped bass and bluefish that will be seen all year are making their way up the Chesapeake, the stripers on their way to the spawning grounds and the blues in hot pursuit of menhaden, the Bay's summer baitfish.

By June the big fish will have moved on to ocean waters off New England and the Bay will be loaded with smaller fish. "I can guarantee that the biggest fish I'll catch all year will be between now and May 25," said Sullivan.

It is time then to be trolling in the middle Bay, keeping in mind that until May 1 any striped bass over 32 inches in length must be returned to the water. That's Maryland law, aimed at protecting stripers on the way to spawn. There's no bluefish regulation.

Spring is the easiest trolling season because the fish, like the ocean-going vessels that use the Bay, follow the deep channel that once was the Susquehanna riverbed.

You don't even need a depth-finder. Just troll along the edges of the main ship channel, well marked by huge buoys.Most fish will be caught at depths of 20 and 30 feet, but they will generally be suspended in water 80 feet deep or more. WEIGHTS -- To get the lures to the proper depth requires wire line and sinkers of from 3 to 28 ounces. Trollers fish a "spread," meaning several lines at various depths. To keep them from fouling each other, they are played out at different distances behind the boat. Thus a line with a 3-ounce weight is fed 200 feet out behind the boat, while the one with 28 ounces is dropped only 55 feet. They both end up at close to the same depths.

The more lines out the better the chances. Some charter skippers fish as many as nine lines. LURES -- Bucktails are preferred in the early spring, with a split porkrind attached. Big spoons also work well. Surgical eels are favored later in the year, starting around June. All three are rigged the same way. The trolling line is hooked with a snap swivel to the in-line sinker. A 30-foot length of 50-pound test monofilament leader hooks by another snap swivel to the back end of the sinker. The lure is tied to the end of the leader. Halfway down the leader a barrel swivel should be tied in to keep the leader from twisting. SPEED -- Troll bucktails as slowly as possible. Spoons should be trolled just fast enough that the rod tip bobs about once a second as the spoon works in the water. Rubber eels are trolled fastest, and should be watched briefly on the surface to make sure they are coiling through the water in a life-like way. LOCATION -- Troll anywhere from the upper Bay to the mouth of the Potomac and below. Stick to the edges of the main channel in the middle of the Bay and be patient. There won't be a great deal of action, but when a strike comes it's likely to be a huge fish.