Torrential rains, lightning and lakes of casual water in the fairways at the Master: How declasse .

Craig Stadler and Ed Sneed, both their nearly-unknown names misspelled on the leader boards, plodding to a tree-shot lead at the tournament's midpoint: How gauche .

A dozen soaked golfers left on the inundated Augusta National course at sundown, their rounds suspended until morning. One was a man called Mr. X who was just a shot off the course record with three holes to play: How tacky.

This was indeed Bay Friday the 13th for public image-polishing at the gamorous 43rd Masters.

A two-hour rain delay while four inches drenched the picnic was untoward enough. After all, serene Rae's Creek should not turn into a whitewater torrent out of "Deliverance" as it passes under Hogan Bridge.

However, Stadler with his 66 and Sneed with his 67-putting themselves at nine-under-par 135, three shots in front of tubby Leonard Thompson and Ray Floyd-were simply one step above gate-crashers at this golf high tea.

All the right sort of masters people, chaps like Tom Watson at 140, tied for fifth with Joe Inman, and Jack Nicklaus, with three others at 141, committed every sort of faux pass whenever they got close to the lead.

What sort of men were these tromping off the hallowed 18th green with filthy shoes and matted, uncombed hair, then claiming to be leaders?

The 5-foot-10, 220-pound Stadler, looking like a soggy walrus with his damp moustache, never had made the Masters cut before.

"My best previous finish here," he deadpanned, "was the gallery on Saturday."

Stadler was not insulted that the huge 18th-green scoreboard identified him as "Craig." After all, he allowed, the biggest previous tournament that he had ever won in April was "my club championship."

Sneed, an 11-year tour veteran who has won just three tournaments-none major-always has been the walking personification of the PGA Tour's nagging identify crisis.

"Yes, I guess you could say I have an identity problem," Sneed said, after the best Masters found of his career. "As I walked up the 15th hole, the scoreboard read, 'Sam Snead-seven under par.'"

Seldom has the Masters had two such modest and engaging leaders-both men downplaying their chances to win.

Reviewing his athletic career, the sweet-swinging Sneed pointed out that he was the No. 4 man on his Granby High golf team in Norfolk, Va., and that he might have played basketball at Ohio State, but "I wasn't big enough, quick enough or good enough. Otherwise, I had no problems."

Stadler, who says, "I don't eat a lot. . . food just stays with me well," managed to play high school football "for two weeks."

If Sneed and Stadler, both steady pros who were on last year's top 66 exempt list, have long remained in the shadows, pity poor Miller Barber, known as Mr. X for his knack of remaining anonymous. Playing perhaps the best round of his life, he was seven under par through 15 holes, including an eagle 3 at the 15th, barber was caught by sundown and will resume his round at 8:30 a.m.

Barber will have all night to think about his delightful dilemma. He needs to play the last three holes one under par to tie the course record of 64, and two under par to break the record. Both, to be frank, are unlikely eventualities since 16-17-18 is a difficult stretch.

True to form, Barber's discontinued round went underpublicized since Masters officials did not bring him to the mammoth press area for an interview. Barber stands at four under for the tournament, tied for seventh with nicklaus, Lindy Miller, Severiano Ballesteros and Lou Graham.

Of the three past champions in that top 10-Nicklaus, Watson and Floyd-it was Floyd who played and talked most like a man about to lie in the weeds and make a move.

I'm playing better than I was at Greensboro (where he won)," said Floyd, salting his soft-spoken understatements with one boast. "I've hit 32 greens in regulation in two rounds and 2've reached all but one par 5 in two shots."

It was Watson and Nicklaus who felt like kicking themselves at day's end. Watson reached seven under par after birdieing the 13th and still had the easy, for him, 15th left for another birdie. But for the second day in a row, Watson underclubbed himself on his long second shot at 15 and landed close to the middle of the lake in front. This time he looked skyward and let out a favorite hacker's oath. True to his plucky form, he wedged to within a yard and saved par.

Two holes later, Watson avoided catastrophe again. After driving into the trees, airmailing the green with an iron, then putting from the back fringe all the way across the green down into the fairway in front, Watson chipped-and-putted to save a bogey.

Nicklaus, after shooting a 39 on the front nine that had him on the verge of losing contact with the leaders, pulled himself together for a sterling four-under 32 on the back, including a 40-fott birdie putt that hung on the lip and fell at the last hole.

"I had a six-foot birdie putt at the 11th and I said to myself, 'For crying out loud, let's see if you can't take the putter back and bring it through on the same line for once' . . . I just listened for it to drop in the hole . . . I started gaining on it after that.

"At the 18th, I don't know why but I couldn't see a reason not to make that putt. That's after 35 straight when I couldn't see any reason why I should make one . . . that was the first putt I've made over six feet in two days."

On this day that saw a tornado warning posted on the course, and a thunder-and-lightning barrage around the 18th hole that, Inman said, "danced all around us as we ran in," it was Stadler and Sneed who played like little twisters.

Stadler, the '73 U.S. Amateur champion, after finishing the first round with five birdies in the last seven holes, started the day birdie-birdie-birdie-par-birdie for an incredible nine-under-par streak over just 12 holes. His other 24 holes have been even par.

"I must be a good mudder," he said. "My best previous round in a major tournament was a 67 in the PGA last year in the rain and it moved me past a lot of people. I finished sicth," a finish he probably would relish here when the mud settles.

The baggy-pants Stadler, who looks moore like he should be carrying a bag for one of the permapress pros than blasting long drives, has, in recent years, mastered what he calls "a pretty terrible temper."

Did Stadler ever throw clubs?"

"I threw everything," he said.

Sneed, on the other hand, never would throw anything. He is the player director of the Tournament Policy Board. Today he was the director of some marvelous iron shots that peppered the pins all day on greens softened by the morning drizzle.

"I wasn't excited with my 68 in the first round," said the handsome Sneed, no relation to the more famous Sam and J.C. of the differently spelled Snead clan. "But I'm sure excited now."

Sneed was so close to the pin all day that, according to his estimates, if he had made nothing longer than a 12-foot putt he could have shot 60. More realistic than the hope of draining every makeable putt is Sneed's desire to continue saving par on those rare occasions when he misses a green.

"I've saved every one so far," he said. "I hope I don't start thinking about that tomorrow."

Despite the leaders' seemingly large three-shot bulges, every golfer who is under par here still thinks he is in contention.

"There are people who aren't even on the leader board who have an excellent shot," said Floyd. "It's all going to do a lot of flip-flopping."

One man got his just reward today. Hubert Green killed a three-foot-long water moccasin Thursday in the creek that fronts the 13th green, beating it to death with five strokes of an iron. Wits, still remembering Green's short missed putt on the 18th last year, claimed it was the first time he had not backed off a three-footer at Augusta.

Today Green fired a 69, with a birdie at the 13th. There were no snakes in sight. Even a water moccasin wouldn't come out on a day like this. CAPTION: Picture, Craig Stadler closes eyes in disbelief as birdie putt hangs. UPI