There are a million ways to catch fish. The big bass boys will be showing the latest and greatest next week when they descend on Lake Gaston for the $62,500 Virginia Invitational.

Then there's the old school. We've come a long way, baby, from the days when man relied on his canoe and his brains to find the fighting fish. Just for fun a fishing pal and I took on a new and delightful spot, Lake Manassas, with nothing but our wits and our poles Sunday to see how we'd do.

We did zilch.

Which is not to say we learned nothing. For one thing, we learned about LakManassas, which is a gold mine just 45 minutes from Washington.

For another, we learned how frustrating it can be to try to read a lake when everything is going against you: The water was too cold, there was no one else on the lake, we didn't have all the bait and lures we wanted and our little john boat and its tiny electric motor were just too slow to take us every place we wanted to try.

Manassas Lake was built about 10 years ago by scouring out a trough and damming Broad Run to create a supply of drinking water. For eight years it was fishing turf only to interlopers who knew the diffcult route back through private fields to the banks.

Then last summer the sneak fishermen became a problem. The Manassas town fathers decided it would be better to open up the lake through a concession so they could control the fishing.

They looked for bids from concessionaires. John Ryan, a retired army officer with a brick home on the hill overlooking the lake, decided to bid. He won by default. Nobody else bid.

The lake opened for a few months last year and will open for a full season next weekend. Ryan is a quiet, hard-working guy with one concern: he hopes Manassas won't turn into another Burke Lake, overfished and abused by weekend anglers.

He should worry. Manassas is a gorgeous lake with a nice balance of game fish. It has both native small-mouth and large-mouth bass, a rarity, plus catfish and bluegill and crappie in abundance. It's a beautiful place to putt around, even if you don't hit the big ones. Rolling fields and stands of cedar and hardwood slope down to water's edge. To get to the lake you drive through cattle pastures where placid Angus graze.

The 850 acres of water offer some pluses and minuses for fishing. The big minus is an almost total lack of structure - the brush piles and logs and stumps that fish love to lurk in.

"When they built this lake they bulldozed it clean," said Ryan. It's like a pie plate down at the bottom.

But they also bulldozed it deep, and that can make for good fishing along the steep dropoffs near shore. When you find one you can work your way down until you find where the fish are. Then you're set for the day. Or at least for awhile.

Another plus is that no one really knows the lake. A newcomer has as much chance as anyone of finding the big fish. The law at Manassas is no power boats - only john boats with, if you want them, electric motors - so you won't get outclassed by a fancy bass boat.

If you haven't got the time to learn the lake, Ryan has a piece of advice that he picked up in his youth. "Find the oldest guy on the lake and follow him around. He'll be the one that's had the time to do it right." Sometimes the oldest guy on the lake doesn't like that. Bring your binoculars. Technology has its place.

One angler who has learned Manassas is Ken Steadman, an Army major from Vienna. He didn't get out last summer because he was on the Korea desk here when U.S. soldiers were clubbed to death at Panmunjom, but by fall the crisis had eased and he had the time.

Steadman also had the honor of catching the first bass in Manassas in 1977. He pulled it up through the ice on New Year's Day.

Last fall he got a long look at the lake. He finds it tougher than Burke Lake because it's bigger and so more difficult to get to all the good spots and because it's deep and unprotected from winds.

But it's not too tough. In 10 or 12 trips last year he figures he pulled in close to 200 bass, though he put many back. Among the ones he kept were two he has had mounted on his wall: a 61/2 pounder and an eight-pounder.

Steadman favors fishing Manassas with crank baits and light tackle. He's had goodluck on the steep-sided banks particularly near cliffs of broken rock. And he feels there is structure - topographical structure from the bulldozers' carving in the deep spots.

Steadman's advice: fish Manassas in the late evening in the spring and in the mornings later in the summer. He tested the water last week and recorded 46 degrees. That's too cold for bass action, but he guesses when it gets 55 the bass will be "real active."

"In the next three weeks we'll start to get prespawn schooling; in three to six weeks the actual spawning will start and the big roe fish will move into the muddy flats. That's when you can get your lunkers," Steadman said.

And that's real fishing.

To get to Lake Manassas, take Route 66 to Gainesville, then 29-211 for three or four miles to Route 215. Turn left and follow the signs. The tariff is light: 50 cents a day per fisherman, $3 to rent a john boat. Hours are dawn to dusk.