It was just after the final preseason scrimmage, Navy's offense had been disgraced and Coach George Welsh was saying, "I can't believe we're that bad. You know, it reminds me of 1975. The offense couldn't do anything then, either, but as it turned out it was because the defense with Chet Moeller was so darned good."

With only one veteran in the secondary and a hole at defensive right tackle, Welsh did not think this year's defense was all that good. He was genuinely concerned in season's start that the Mids were in for stormy sailing.

Now, after five games, Navy boasts the best defense in the nation, the same rating the Moeller group boasted after five games before closing at No. 3. But this Navy team is undefeated, its offense has rolled up 149 points and the Mids are ranked No. 17 by The Associated Press No. 20 by United Press International.

"I think that's part of it, that's probably a sound observation," Welsh said yesteray when asked if perphaps his defense had fooled him by causing those early September offensive boo-boos. And he added that the No. 1 defensive ranking was "certainly a surprise."

Navy's defensive heroes include safety Fred Reitzel, a quarterback last year who has recovered three fumbles and broken up three passes despite missing a game with a wrenched knee; middle guard Terry Huxel, a converted fullback who in two games as a started has made 17 tackles, six for losses totaling 31 yards, and end Charlie Thornton, a linebacker during 1977 spring practice who already has made 39 tackles, six for losses totaling 38 yards.

Cornerback Bob Wilson was a letter winner at wingback a year ago. Rover Gregg Milo, the only veteran in the secondary, was a tailback until the 70-14 disaster at Michigan two years ago, when he was shifted to plug one of many defensive holes. End Mark Stephens saw previous duty at middle guard and linebacker.

Welsh, who tries to put his best athletes on the field regardless of position, was concerned about his inexperienced secondary. He was not alone.

"If anybody had told me at the beginning of the season that we'd be the No. 1 defense in the country after five games, I'd have said it was a dream," Wilson said. "But we believe in each other. We have a lot of confidence and pride in each other. We understand the linebacker and linemen's jobs and they understand ours. We're more of one unit then before, really together."

"We had a lot of questions unanswered and a lot of guys were wondering if their jobs were secure when the season started," Reitzel said. "We've got a lot more pride now. We have confidence in each other. If one guy makes a mistake, there will be somebody there to help out."

"We just hadn't had much experience," said cornerback Chuck Zingler. "We knew we were young and we worked very hard.We still have to work hard. If you let up on one play in the secondary, it's seven points."

Milo has made only 15 tackles, amazingly few for a rover, but nobody is complaining about his work.

"There have been few opportunities," Milo said. "The linemen and the finebackers are stopping all the guys. I've probably had 15 fewer chances this year - and I think it's great."%TBesides their overall leadership in defense (130 yards a game), the Mids lead in fewest points allowed (4.8 a game), rank second in rushing defense (56 yards) and fourth in passing defense (74).

"You can attribute part of the pass defense to the excellent rush," Milo said. "The passer can't throw the ball on his back."

A year ago the secondary wore twels around each man's waist and prided itself on its pass coverage. This year there are no such cliques.

"We're all close friends on and off the field, which is unusual for the academy," said 6-foot-6, 248-pounds John Merrill, the intimidating tackle known as "Dr. Ohm."

Huxel started preseason drills as No. 3 middle guard behind Tommy Thompson and A.B. Miller. He is No. 1 now and can't thank Thompson and Miller enough.

"I was new to the position and at first it bothered me, but I love it now," Huxel said. "The other guys helped me a lot. If they saw me do things wrong or noticed something in games that would help me, they told me."

The No. 1 defensive rating and Navy's top 20 status have had little impact on the attitudes of the players.

"When you're talking about the polls, you're talking about some awful good teams," said linebacker Tom Paulk, the team's leading tackler with 40. "I'm just not sure we're really that good. But we're proving each week that we can do the job."