The stench of cheap booze, stale cigarettes, newsprint and pre-air conditioning sweat wafts off the screen in “The Rum Diary,” Johnny Depp’s second shot at paying tribute to his friend, the late journalist Hunter S. Thompson. Though it only rarely reaches the level of gonzo farce that it might have been, “Diary” is still an agreeably drunken stagger through the novel Thompson based on his formative year as a writer — 1960 — which he spent drunk, getting into trouble and first tangling with “The Man” in Puerto Rico.

Paul Kemp (Depp) has come to San Juan for a job interview at the San Juan Star newspaper. He’s made a bad impression by being late and seriously hung-over for his meeting with Lotterman, the editor.

“Conjunctivitis,” he insists.

“This is not the Last Chance Saloon,” Lotterman (Richard Jenkins) gripes, demanding to know what kind of drinker he’s dealing with.

“At the upper end of ‘social,”‘ Paul lies. “I’m poised to give it up!”

Writer-director Bruce Robinson (“Withnail & I”) packs the script with pithy Hunter-isms, hurling many of Thompson’s euphonious locutions at us in this opening scene. Puerto Rico, with its two languages and two flags, is “like England with tropical fruit,” Lotterman explains.

Kemp settles in, but his cynicism (he’s a failed novelist) works its way into his stories, the bowling alley tourists who are “beasts of obesity … Great Whites … gluttons” and “locusts.” He has to learn “Nobody wants what’s wrong with the place,” and if not from Lotterman, perhaps from Paul’s cynical colleagues, roommates and fellow drunks — photographer Bob Sala (Michael Rispoli, pretty good) or columnist-on-a-bender Moberg (Giovanni Ribisi, WAY out there).

It’s the oily press agent Sanderson (Aaron Eckhart) who sells Paul on Puerto Rico’s place within the American Dream, which was to become a running obsession with Hunter S. Thompson. The island is “a gold mine” thanks “to something that doesn’t exist — land.”

And Paul listens to Sanderson, because the guy is offering to pay him off and because Sanderson has the most gorgeous blond girlfriend this side of Monroe, a clothing-optional bombshell perfectly embodied by Amber Heard.

Among the supporting players, Ribisi stands out as he plays Moberg as almost a Thompson prototype — ever blitzed, always in sunglasses, stealing soaked filters from the Bacardi rum factory to distill his own hi-test brew from. He staggers everywhere, rages at authority and listens to old Hitler speeches on the phonograph, and can’t understand why others don’t nod in approval when he asks, “Shall we have some Adolf?”

Nothing much happens here that we don’t see coming — cops and cockfights, flirtations and drug trips. Depp is entirely too old to be starring in a coming-of-age-as-a-journalist tale. (Thompson himself was 21-22 while he was there.) But Depp makes the performance work by suggesting a burn-out case in need of a second chance, someone world-weary enough to recognize the ethical temptations of the job and the alcoholic temptations of the island.

“Rum Diary,” however predictable the trip and perfunctory the arrival, is worthy because it’s just plain fun to watch the actor who so nailed Thompson in the cult hit “Fear and Loathing in Las Vegas” work through the earlier version of what would become Thompson’s obsessions — Nixon, who “lies like he breathes,” hallucinogens and writing “the truth,” as he sees it, come what may. As vanity projects go, this one’s a perfectly passable Hunter S. Thompson valentine.