Raoul Duke in Fear and Loathing in Las Vegas, Johnny Depp (Pirates of the Caribbean: On Stranger Tides) is back in the hallucinogen-infused world of Hunter S. Thompson in The Rum Diary, director Bruce Robinson’s adaptation of Thompson’s second novel.

According to Hollywood legend, Thompson first wrote the novel in the 1960s but didn’t publish it until 1998 at the urging of Depp, who found the manuscript in Thompson’s Colorado home. Depp’s prominent role in both the novel and film is almost too meta for its own good, but you’ll forget that connection the second Depp’s Paul Kemp, hungover and in his underwear, opens his hotel curtains to reveal the film’s true star: San Juan, Puerto Rico.

Kemp is a New York journalist who, in 1960, relocates to Puerto Rico for a freelance job at The San Juan Star. After befriending sensible photographer Sala (Michael Rispoli, Blue Bloods) and constantly drunk semi-reporter Moberg (Giovanni Ribisi, Avatar), he is swept up in a world of 24/7 inebriation and ridiculous situations.

He somehow finds time to butt heads with his editor (Richard Jenkins, Friends with Benefits) over their conflicting ideas of journalism, to get involved with a shady entrepreneur (Aaron Eckhart, Battle: Los Angeles) and to flirt with said businessman’s beautiful girlfriend (Amber Heard, Drive Angry 3D).

The Rum Diary‘s greatest strength is its depiction of ’60s Puerto Rico in all its physical splendor and political instability. Though the sky is almost always blue and the palm trees are always a brilliant green, underneath the superficial elements are the poor ghettos filled with angry locals upset at white domination of their land. Any journalism major can appreciate Kemp’s relentless search for the truth.

Everything else is hit or miss. Anyone expecting more of the acid trip that was Fear and Loathing might be disappointed that, minus one scene, most of the antics take place in the real world yet somehow manage to blur the line between plausibility and insanity. As cool a visual as it was, can you really make a flamethrower out of a lighter and 470-proof alcohol? For that matter, is 470-proof alcohol even a possibility?

As much fun as it is to watch Depp in one uncomfortable situation after another, his poorly hidden Eurotrash accent still makes me think he is about to set sail for Tortuga. With the exception of Ribisi, who gets the best lines and has one hilarious moment involving Adolf Hitler’s voice on vinyl, most of the other performances are caricatures.

The Rum Diary makes for a fantastic travelogue of Puerto Rico, examination of its ’60s culture and the role journalism played in it. The problem lies (ironically) with Thompson’s trademark manic humor, which is an acquired taste and only sporadically hits its mark. It’s this imbalance between the realistic backdrop and the ludicrous adventures of Depp and his crew that makes The Rum Diary a somewhat fun diversion — but nothing more.

VERDICT: Puerto Rico comes alive and some of the situations are absurd enough to amuse, but boring characters and inconsistent humor make The Rum Diary an ultimately forgettable experience

diversions@umdbk.com