I have been lying on the beach watching bad judgment jiggle by. I am smug, my rump is snug, for I have a bathing suit that fits. It's a serviceable suit from last season -- a blue-and-white polka-dot, well-made, well-fitting if "classic" cotton tank by Ralph Lauren. I went through hell to find it a year ago May, and I treasure it. I care for it with obsessive tenderness. After one season, it is kind to my body and still snaps to at all critical points. I'll wear it as long as it will have me.

Thus it was in the interest of social research that I joined my sisters this year in that nasty rite of late spring, when female America gathers its moxie, sucks in its tummy and sallies forth to Buy the Bathing Suit. Stepping into the swimwear fitting room of a Major Department Store is not an expedition for the faint of heart:

The background music is from "Jaws," the menacing part where the fin is cutting through the waves. Dum-dum, dum-dum. The camera pans a narrow white corridor, doors opening and closing, flashes of parrot green, florid pinks, glimpses of innocent, exposed human flesh. We hear shrieks. Keening. And then a woman's tortured cry:

"Ohhhhh, oh lord. What sadist made this thing?"

Discarded tops flew like distress flags everywhere. In the nylon-and-spandex trenches, I commiserated with fellow shoppers. In fact, in all the years I've endured this ritual humiliation, I've never heard such chatter or seen so much naked emotion. Hold up one of those $65 stretchy slingshots, and four or five Furies would pipe up:

"Do you believe that?"

Sisterhood is powerful in the Lycra clinch. Behind mirrored doors in the fitting room, women are honest with one another ("Cele, I'd hate to see you do that. It's not for you, Cele"). They are gentle ("Maybe a sensible Jantzen, Cele. I hear skirts are back, doll"). But most of all, women are angry ("Whoever made this suit," gasps Cele, "should choke on it and die").

Most fitting-room attendants I spoke to said they hate pulling swimsuit duty. Women are panicking, despairing. Wearing dark glasses and sniffling, they return armloads of unsuitable suits. Sometimes they thrust them back and snarl rude things.

The fact is, we're mad as hell. Women of all shapes and adiposity. Something's going on, and even the skinnies got them lowdown nothing-fits blues. This is because the swimwear designers have forgotten we're human.

In years past, they were sympatico. They cuts suits for real bodies. But they've turned on us in recent seasons, pushing sheer little nothings, suits "thonged," cut out, fish-netted and diapered. Their physics are fiendish, cantilevering body parts in sets of tiny pouches and slings. Sometimes there's just not enough to them -- I measured the twin equilateral triangles that served as the top to one size 6 bikini and found them to be an astonishing three inches per side. Even if you're a double-A, such geometry gets an F.

Overall, new-wave swimsuit crimes fall into a few basic categories:

The High-Thigh Conspiracy. This is by far the most egregious of recent suit crimes, and the one that goes most blatantly against nature. Despite the incontrovertible fact that the female pelvic region is broad by design (we're talking bones, not flesh, here), the trend has been toward an ever-narrowing isosceles triangle -- bathing-suit bottoms cut very high on the hip and excruciatingly narrow from crotch to navel. Rear panels exhibit a similar philosophy of style: Cut high, and let the cheeks fall where they may.

I tried on 10 suits "normal" in every way but the legs. They were Gottex and Vittadini's, hot Kamali's, Coles and the like. The leg holes all rose to my hipbone or beyond. We women measure an average of two to three inches between the top of the thigh and the bottom of the hipbone. But it may as well be a six-lane interstate. A lot goes on in this critical span -- a major bone and joint, the natural crease between leg and torso. It's not a clean, sculptural plane. Contrary to fashion-mag folderol, the high cut does not make a body look as though it has more leg. Just more.

No one is happy about this trend, with the exception of electrolysists and bikini-wax emporiums. Surfside, a nervous tic has spread across the land -- the need to tug one's suit back in place when the natural motion of (heaven forbid) walking sends the leghole creeping toward your neckline.

The high-hip plague has afflicted us for about two seasons now. But this year's special coup de gra~ce seems particularly cruel: a flounce, a ruffle or a floppy bow -- placed right at the hipbone, or on the derriere. Why stop there? Why not attach a flashing yellow highway blinker, something that says, "Yo! Hips here! Hey, mama! Wide load!"

The Wet T-Shirt Syndrome. Many swimsuit designers are no better than those beery barroom yahoos who shake up a seltzer bottle and wet down women's braless, T-shirted chests. I cruised hundreds of suits, and more than half had no support or lining over those sensitive pulmonary places. Rise glistening from the surf in these things and the entire beach population becomes unwitting judges in a wet contest. This is fine if you're a seltzer-bottle kind of gal. Not so swell if you want to keep your 34Bs to a discreet level of jiggle, jounce and jut.

The Rubik Suit Gambit. Saleswomen tell me that at the start of each season, it's often necessary to receive store buyers' instructions as to just how certain of these little nothings wrap around one's somethings. The trick suits are hell to get into, but blessed easy to fall out of. They feature cutesy cutouts and intricate lace-ups, Bedouin wraps and cat's-cradle crisscrosses. They are held together by metal rings, ties, clips, Velcro and the grace of God.

I saw many suits that would stump Rubik. But the winner in the trick category, hands down, is Donna Karan, a terrific designer who normally displays knowledge and respect for human anatomy. Karan's little black suit has a sumo-wrestler bottom -- central thong, lotsa cheek. There's a plunging neckline and lots of wrapping in between. The item is so tricky, it comes with instructions and diagrams -- five of them -- explaining how to get into the thing (" . . . pull flap snugly to cover and hug bottom . . .").

It was a challenge I couldn't resist. But even with instructions, it took me 6 1/2 minutes to flap and wrap my way into one, and I nearly strangled twice. The mirror revealed a panting woman in an $85 diaper. All this intricate body macrame' leaves you energy for little more than lying prostrate on a blanket. Just as well, I suppose. Stand up, and gravity might be your undoing.

I unraveled the dreadful thing and got back into my jeans, depressed. A woman perpetrated this horror. Donna Karan, the regular gal who does those down-home "never let 'em see you sweat" deodorant commercials, is suggesting that a woman sashay up to the hot-dog stand flashing more cheek than the Coppertone kid. I have to wonder, would she?

Leaving the store, I strolled through the men's swimwear, where the most recent trend has been baggy. Boxer-like and forgiving of the weekend six-pack. Bikinis and Speedo racing briefs are available. But they're given far less space on the rack, less still on the beach. Men are creatures of comfort, and their common sense is rewarded with racks of wearable garments. No fool is going to try and sell a sumo thong to a balding cost accountant.

So why us? Because we've been taking it, ladies. These designers are counting on our desperation and bad judgment. I say it's time to take a long hard look in the fitting-room mirror and holler, "ENOUGH." Let those misogynist maillots rot on the hangers.

And if you waver -- if you get the mad urge to thong or diaper, to show more thigh and belly than a spitted game hen -- ask yourself these questions, which I overheard in the fitting room:

"Pretend you're sitting on your beach blanket, Cele. You see yourself walk by. In that suit. What would you say, Cele? 'I hate her?' Or, 'Do you believe that?' "

Believe me, Cele bought the sensible Jantzen. ::