There is a much more detailed exploration of The Rum Diary here.
One mustn’t forget, in looking at the works of Hunter S Thompson, to go back and visit his first book, which was ‘lost’ for decades until its eventual publication in 1998. This is different from Thompson’s other books in that it was a genuine attempt at a novel, with a plot and stories that didn’t necessarily happen to the author in real life, but were merely inspired by his surroundings. The book predates Gonzo and Thompson’s journalistic innovations, and comes from the period in his life when he was just another writer, trying to cut it working for a newspaper, and trying to write novels like his idols – Hemingway and Fitzgerald. Yet, even in those early days, Thompson was mapping out his future. According to David Hamilton’s memoir of his meeting with Thompson in South America, the young man was talking about journalists as participants and even actors, helping the events around them to unfold, rather than noting them as an outside.
One can certainly see the early signs of what Thompson’s writing would become, though it never began to peak for another decade. As William Kennedy said,
The tools Hunter S. Thompson would use in the years ahead — bizarre wit, mockery without end, redundant excess, supreme self-confidence, the narrative of the wounded meritorious ego, and the idiopathic anger of the righteous outlaw — were all there in his precocious imagination in San Juan.
Although one could claim any Thompson book to be a novel, due to the dubious claims and distorted versions of true events, The Rum Diary is almost entirely fictional. It is, however, based on the world around Thompson at a certain time. In 1960, prompted by a strange friendship with William Kennedy, and the appearance of his friend Bob Bone, he took a job at a magazine in San Juan, Puerto Rico. The magazine, however, didn’t turn out to be ‘the Sports Illustrated of the Caribbean’ that Thompson expected, and he was trapped in Puerto Rico, writing about bowling, for bowlers. He was not happy.
Thompson found himself living in a beach shack, in some strange paradise. However, the work was demeaning. Thompson’s ego at this point in his life was incredible. He wrote intolerably high-minded letters to publishers and editors, and yet was somehow employed by a low-class bowling magazine, doing nothing more than jamming bowlers’ names into print.
They were introducing bowling to Puerto Rico. I had to go out and cover bowling every night in San Juan. Bowling was going big. Bowling alleys were popping up everywhere. What could you say about bowling?…But about half my work was making sure every bowler in San Juan got his name in the magazine…ever since then I’ve hated the world of bowling.
To keep himself interested, Thompson was writing mediocre travel pieces for newspapers across America, and wrote a few pieces for bigger publications. In between, he earned work as a male model.
Soon, however, Thompson persuaded his old friend Paul Semonin to come to San Juan. Semonin landed a job at the Star, and rented a better place with Thompson, outside the city. Soon Sandy Dawn Conklin, Thompson’s common-law wife, was living in the crowded beach hut. She was Semonin’s ex-girlfriend, and the couple’s nudity and outward sexuality made for an uncomfortable stay.
During this period, Thompson published another piece, this time for his hometown newspaper, which had for the duration of his stay listed him as a Caribbean correspondent. The article was about Semonin, describing him as a wandering Louisville son in the Caribbean, honing his skills as a painter. However, the article was completely fabricated, in no way endorsed by the subject, and contained quotes from Semonin that had never been uttered. Semonin was enraged.
Soon after this, Semonin and Thompson were arrested after a dine-and-dash attempt, and spent part of a night in jail, before being rescued by Kennedy. It was all Thompson’s fault, and he played out the whole affair as a theatrical farce, calling the police Nazis, and again enraging his friend.
By the time that Thompson escaped Puerto Rico (through an attempt to get to Europe, but only making it as far as Barbados) he had the idea of a novel in his head. The idea resulted in The Rum Diary. This novel drew heavily from his experiences in Puerto Rico, but was not entirely autobiographical.
He wrote the novel between California and Colorado in the years following his departure from the island, but it was only following the success of his collections of letters that Thompson thought to look back at his old works, at his fiction. When he did, he found The Rum Diary as a thousand-page manuscript. He cut six hundred pages and the result was a pleasant surprise for him and for the critics, who were expecting an embarrassment.
But how much of The Rum Diary was truth, and how much fiction? Ralph Steadman, his old friend and the other half of Gonzo, said that, ‘It was him again, doing an assignment in Puerto Rico, doing small-time journalism.’ Indeed, it’s easy to see that the surroundings in the book match other accounts, and the character of Paul Kemp doesn’t differ too greatly from that of Hunter S Thompson, but this was a time when Thompson was a young writers with his sights set firmly on writing novels, and his life acted as inspiration. Perhaps The Rum Diary is a novel like On the Road was a novel, just a cover for a twisted reality. Or perhaps it was indeed a novel in the tradition sense, and Thompson’s imagination had been set into action by his experiences as a struggling journalist.
The novel starts with a description of the setting and background, and quickly moves into what is effectively the story of Paul Kemp’s departure from New York. This doesn’t exactly fit with the story of Thompson’s departure, but it’s possible to see Thompson in the protagonist as he speaks in quick, sharp bursts of angry speech. “You rotten old bastard,” tells an old man after the guy almost sits on Kemp’s typewriter. One hardly needs to stretch one’s imagination to see any incarnation of Thompson in this situation, responding in that manner.
When Kemp arrives in San Juan, to write for the San Juan Daily News, we are presented with a deviation from the truth, in that Thompson clearly arrived for a job at El Sportivo. But this is what The Rum Diary is. It is a novel heavily influenced by Thompson’s time in San Juan, but not specifically about it. It is a re-imagining of the period.
Soon Kemp is talking with Bob Sala, the staff photographer, who asks the newcomer why he came. ‘A man could do worse than the Caribbean,’ Kemp explains. Sala disagrees, and soon the novel departs from the brief glimpse at paradise, and enters the murky world of professional journalism. Kemp realises he has walked in on a bunch of drunks, with the good writers and good people dropping like flies.
From there on the novel details the racial tensions that Thompson experiences, and the run-ins with the law. Sex is thrown into the deal, whereas it seems to be missing from so many of Thompson’s books. This was clearly inspired by Thompson’s relationship with Conklin during her time in San Juan.
You can read much more about The Rum Diary in this 2020 essay or in High White Notes: The Rise and Fall of Gonzo Journalism.
 Hamilton, D., ‘In an Innertube, On the Amazon’ Michigan Quarterly Review 29 (1990) p. 382
 Backcover blurb of The Rum Diary
 Thompson, Gonzo Papers, Vol. 3: Songs of the Doomed: More Notes on the Death of the American Dream (Simon & Schuster: 1990) p. 65
 McKeen, Outlaw Journalist p. 340