A COUPLE OF FRIENDS OF MINE used to take Jimmy Buffett intravenously, back when he was a cult figure, him and his imaginary Coral Reefer Band, back before his 1977 smash "Margaritaville" salted the airwaves 40 times a day on every pre-programmed all-the-kids-are-doing-it AM radio station in the country. They still made his concerts last year, but mainly for the sake of the old songs, like "They Don't Dance Like Carmen No More," and for a commode-huggin' good time. They thought "Margaritaville" was a lemon.

But all roads lead to rum and last month they went down to Winter Haven, Florida, chasing the Red Sox Spring Training Tan. They didn't really arrive until the day they wandered out on this teak-wood deck with an ocean view and thatched umbrellas over the ashtray tables where you set the kind of Caribbean concoctions that come in gutted coconuts and topless pineapples; that was when, with the help of a little juice, Jimmy Buffett's Margaritaville music came marimba-ing out of the loudspeakers. This is Florida, man! You may not be no pith helmet, mama honey, but I sho do lak the way you squeeze my tanning butter. Make that a double rum punch, bubbles. Me and my Foster Grants.

Sunshine and cold liquor and oceans are the bartenders for Buffett's music, and Son of a Son of a Sailor has the same easy-sippin' mix as the Margaritaville music on his last album, Changes in Latitudes, Changes in Attitudes. The title cut, for instance: "The sea's in my veins, my tradition remains, I'm just glad I don't live in a trailer." Or the song "Manana":

She said I can't go back to America soon

It's so goddamn cold it's gonna snow until June

Yeah, they're freezin' up in Buffalo stuck in their cars

And I'm lying here 'neath the sun and the stars.

Or "Fool Button," a potted rocker that's the best song on the album:

Looking for my rentacar

Was the Cordoba blue or red

Tryin' to remember where I put the keys

Tryin' to remember what I said...

It was a fool palace

Double-knit on parade

They pushed the fool button

As the skinny boy played and played Push it.

The aftertaste, though, is something like the last four drinks in a ten-drink evening: They tasted good, you think, but damn if you can remember what was in 'em. Son of a Son of a Sailor takes no chances--the formula worked last time, sent him from Paul's Mall to the Music Hall, frontal-assaulted the Top Forty, and paid for a new sloop, Euphoria II. There aren't but a half-dozen memorable lines on the new album, and even fewer musical quirks, like the cello (the cello??) that follows Buffett down one of his trademark Acapulco cliff-diving voice drops at the end of a line and flattens out the splash. This is shrimpboat country rock all right, but it's all cluttered up with the latest radar and range-finders (like manager Irving Azoff, who flies the Eagles among others), automatic net-spreaders (the Margaritaville sound, over and over), and a string quartet on the fantail. Now it's a matter of watching the gulls wing it for the garbage.

JIMMY BUFFETT USED TO HAVE SOMETHING TO SAY. His music was just about the first consistent merger of Caribbean rhythms and percussion with American folk-rock pop, and it wasn't just pop to begin with. Buffett grew up in Mobile, Alabama, listening to the same Hank Williams and Jimmy Rodgers classics that whelped the Grand Ole Opry Empire of the Nashville Moguls, a philistine crew who breed for violin affinity, not for rasp'n'roll or the truckstop gut-wrench. But the Buffett derivation went the other way, toward the fringes. Lotta room out there on the fringes: Willie Nelson and Waylon "I Don't Think Hank Done It Thisaway" Jennings were there already, Texas, noses to the ground, developing a sound that relied on electric and accoustic and pedal steel guitars with less and less studio multitrack overdub gibberish and more roadband verisimilitude. Buffett, playing solo bars from New Orleans to Key West, Florida, poured chukka into his roadband sound: drunken-sailor crabby-cowbell filled-in reggae rhythms, compounded with clean country whine-guitars, a baying folkie voice and Greg "Fingers" Taylor's wailing harmonica equals shrimpboat rock. Buffett bottled it quick before it fizzed, and the music hasn't changed much over the six albums in the last five years. Buffett's chartbusting last year was the result mainly of promotional considerations and the pull of a big-name producer, Norbert Putnam, who used to ride herd on Kris Kristofferson. Changes In Latitudes sured wasn't a new style--the best song on the album, "In The Shelter," was written six years ago.

Six years ago Jimmy Buffett was up to his eyeballs in a new style, known generally as progressive country, or more correctly, up-country. His comrade pickers'n' grinners were also his best friends, people like John Prine, Steve Goodman, and Jerry Jeff Walker. Like Buffett, they all added their own carbonations to the flat brew of country music: Prine his Appalachian hillbilly twang, Goodman his Chicago blues, Walker just all-out Texas boozing. What they did was blow out the earnest country cliches with fond parodies ("You Don't Have to Call Me Darlin', Darlin', But You Never Even Call Me By My Name"), rocking mockers ("Up Against The Wall, Redneck Mother"), chomping satires ("My Whole World Lies Waiting Behind Door Number Three"), love-into-lust songs ("Why Don't We Get Drunk and Screw"), and bitter-enders much bleaker than the usual tears-in-beers ("Sam Stone: There's A Hole in Daddy's Arm Where All the Money Goes"). The sound was a lot cleaner than the Nashville over-productions in the early '70s, but the revolution, the genre-busting, was in the lyrics.

SAD TO SAY, IT DIDN'T LAST, this mainline no-cholesterol shoot-up in the hardening arteries of country music. Steve Goodman has paunched down into Chicago's home-grown favorite, writing witty little ditties without much punch. Jerry Jeff is falling prey to cirrhosis of the brain. John Prine's upcoming album offers the only hope in the bunch for a bucktooth overbite country record. And Jimmy Buffett, well, he said it four years ago in "A Brand New Country Star": "He's a hot roman candle from the Texas panhandle he can either go country or pop."

If Buffett had stayed country, maybe, just maybe, he might have kept his edge, the edge that cropped up less and less in the later albums: The Muzak of Havana Daydreaming, for instance, also had "My Head Hurts, My Feet Stink, And I Don't Love Jesus." Whatever whammy Buffett still has doesn't come out in the songs he writes nowadays, only in his concerts, because there, his barband background can't help but stomp. Buffett's genial Musak musings are a lot easier to take, too, when he serves them up-tempo.

Basically, though, Buffett's gone pop. For the good times. There's something to be said for artists' suffering: When they're as well off as Jimmy Buffett they don't hang out around docks and slums and all-nite Mini-Marts any more: this year it's casinos and yachtbasins. That's how he's gone from songs like "The Great Peanut Butter Conspiracy," about shoplifting in the hard times, to songs like Son of a Son's "My African Friend." He meets an African guy gambling in Martinique, they get drunk and Buffett scrapes himself up off some steps the next morning to find the guy gone. Sure was a good time, though, huh? There's no bite to it and nothing new.

What's worse is Buffett's recycling in lieu of new ideas. Like "Cowboy in the Jungle" from the new album. It's a vagabond expatriate song with a couple of funny lines, but he did the same idea much better last year in his cover of Steve Good-man's "Banana Republics." And the title cut from Son of a Son of a Sailor is almost a bibliography of the half-dozen sailing paeans he's written before.

JIMMY BUFFETT'S GONE for the good life, sailing the islands, boiled shrimp and cold beer, married to Jane Slagsvol whom he's loved for five years, with Tom McGuane for a brother-in-law and what all. Son of a Son will do no damage to his credit rating--it's a sure AM smash, and you're gonna hear it wafting from the dorm windows come warm weather. But as for me:

Walkin' down new streets the music is loud

Neon signs bring in tumultuous crowds

But I'm just an old man, I'd probably get sore

'Cause they don't dance like Carmen no more.