High summer doesn't come to the Shenandoah Valley until the thimbleberries ripen. Last week the scarlet morsels, also called wild raspberries, were still tucked away in their fuzzy capsules, ready to burst but not there yet.

Likewise in the river, smallmouth bass were on the brink of summer behavior but hanging back. "They're not quite doing it," said Bob Cramer, who guides float-fishing trips in a big, blue inflatable raft. "They're still in a bit of a spring feeding pattern."

Bob Poole and I had dutifully waited until after the start of summer to book Cramer, expecting prime conditions for flyrodding for bass with streamers below the surface and poppers on top. The hotter the weather gets, the harder they strike.

Anglers around Washington can generally count on three annual bites at the fly-fishing apple -- trout in streams in the spring, smallmouth on the Shenandoah and Potomac in summer, then surface-feeding rockfish in the Chesapeake in fall. But sometimes the calendar plays tricks. Then again, anglers have a few tricks of our own.

We put in upstream of Elkton, Va., on a cool, overcast morning for a seven-mile float down the South Fork, Cramer manning 10-foot oars amidships while Poole and I perched in bow and stern, flyrods ready. Most of my time on the Shenandoah has been in canoes, so this was living it up in a stable boat with comfortable seats and someone else providing the horsepower -- and the lunch!

We also had Cramer's local knowledge, which is considerable. As we slid gently downstream, he pointed to cuts and eddies along the bank where smallmouths generally held, and occasionally to rocky ledges in the middle of the river where big ones lurked. But after a half-hour of casting flies imitating minnows and crayfish to his spots, we had little to show for it.

"Here," said Cramer, thrusting a light spinning rod at me. "Try this."

It had to be a joke. At the working end of this outfit was the crudest excuse for a lure I'd ever seen -- a five-inch, ribbed plastic worm that had been impaled on a hook like a banana run through the middle with an ice pick. The sharp end of the hook stuck out undisguised; the whole thing looked as if it had been assembled by a fourth-grader.

"What in the world?"

"We call it the wacky rig," said Cramer, "and believe it or not it works. Try it."

I looked him over carefully for hidden cameras. I could just see the headline: "Outdoor Writer Exposed as Fishing Buffoon!" But the harder I pressed, the more insistent he grew. There was nothing to do but give it a whirl.

So I tossed the unlikely package up near the bank into the same sort of deep eddy we'd been casting to unsuccessfully all morning, let it sink to the bottom and twitched it two or three times. Bang. The line went taut, and I felt the gentle thump of a fish inhaling. I reared back, set the hook and had the first of dozens of plump bass I'd catch that day on the preposterous wacky worm.

"They're just not feeding aggressively the way they should in the summer," Cramer said by way of explanation as we enjoyed a streamside meal of fried chicken. "The water is still cool and cloudy with all the rain we've had, so you have to fish deep and slow."

Which was fine by me -- I'd caught dozens of bass by then, both smallmouth and largemouth, mostly in the 12- to 16-inch size range, which put up a good fight on ultralight tackle. Poole, a fly-fishing purist, stuck with the long rod and was having a harder time. He tried everything from weighted streamers along the bottom to foam poppers on top, but of the few strikes he got, most were little bluegills.

He professed to be unbothered, but an hour or so after lunch he finally piped up to see whether Cramer had another wacky worm outfit aboard. I never thought I'd see the day Bob Poole would stoop to spinning tackle, but there it was.

And a few minutes later he was a happy angler, too, as a 12-inch bronzeback smallmouth climbed all over his offering and leaped a couple of times on the way to the boat.

By the end of the day the flyrods were abandoned, but Cramer assured us that in a week or two traditional summer fly-fishing strategies will be back in play: Streamers during the middle of the day when the bass stay out of the sun under ledges and along the banks, poppers in mornings and evening when they come out to feed with a purpose.

Wacky worm is a generic term, applied to the way a high-density, salt-impregnated plastic worm is hooked through the middle. The best worms to use for this, sources say, are five-inch Yamamoto Kinami Baits or Case Magic Stiks of the same size.

While the technique is new to me, river fishermen say it's been producing fish for a year or two. I'm behind the times, but not alone in my astonishment. "I looked at them the first time and said, 'That can't catch fish, it's stupid-looking,' " said longtime Shenandoah angler Trace Noel of Bentonville, Va.

With summer smallmouth fishing coming on, here are some river bass guides to consider:

Bob Cramer, 540-867-9310 (www.bobcramer.com)

Ed Keller, Potomac Fishing Guides, Hagerstown, 301-582-9404.

Ken Penrod, Life Outdoors Unlimited, Laurel, 301-937-0010.

Mark Kovach, Silver Spring, 301-588-8742.

Tom McFilen, River Hawk Tours, Berryville, Va., 540-955-2716.

Harry and Jeff Murray, Edinburg, Va., 540-436-3964.

Chuck Kraft, Charlottesville, 434-293-9305.

Billy Kingsley, Blue Ridge Angler, 540-574-3474.

For those who want to rent canoes and do it themselves, try:

Shenandoah River Trips, 800-727-4371.

Front Royal Outfitters, 540-635-5440.

Downriver Outfitters, 540-635-5526.

Shenandoah River Outfitters, 540-743-4159.

River & Trail Outfitters, 301-695-5177.

Float-fishing guide Bob Cramer proudly displays smallmouth bass as McLean's Bob Poole admires catch.