Some people are suckers for punishment. How else do you explain a bunch of stand-ups celebrating the end of a gruelling Edinburgh Fringe by staging yet another free comedy show – albeit one on a swanky boat moored on the Thames, rather than a converted stationery cupboard masquerading as a venue.

While at the festival, tonight’s MC, Bob Slayer, was nominated for the Malcolm Hardee award for comic originality. And what better way to mark the accolade by getting steaming drunk over the course of the night. At least he stayed on the boat.

His under-the-influence compering was largely confined to telling women in the audience they had cracking breasts, while one awkwardly extended bit of banter pretty much revolved around him telling another punter she should be a hooker. Well, it is an original way to host a show, even if that woman never returned to the RS Hispaniola after the second break.

First of the acts on stage was Kate Roxburgh, a Londoner now resident in Los Angeles with an agitated, nervy delivery and pride in her role as a geeky scientist. Not that her job had much bearing on her material, as she dumbed down the limited references to the subject. ‘Why do we need a large hadron collider,’ she pondered. ‘Why not a small one,’ suggesting a jerry-built alternative.

References to the likes of Schrodinger’s cat and Pavlov’s dogs featured in her long stream-of-conscience bursts of surrealism, but just as contributions to the noise of random nonsense. There’s nothing especially brilliant about her stringing odd ideas and phrases together, but like many practitioners of this style, she gets a laugh when her breathless delivery suddenly stops, the change in pace when she pulls herself back to normality triggering a response.

‘I have no punchlines,’ she admits, with the same sort of self-awareness that means she’ll joke about rape, then proclaim that it’s the sort of material critics don’t like. Too right.

Charming Iranian-American comic Negin Farsad, pictured started slow, with a few lightweight observations about Britain, and how she had trouble spending Scottish currency south of the border. But once the small-talk was dispensed with, she revealed herself to be a very sharp operator indeed.

Her background as a liberal Muslim clearly informs her comedy, but she goes well beyond the easy ‘I’m so ethnic’ route, having fun with stereotypes but never feeling beholden to them. Her witty and provocative material about picking up a Jewish man in a bar is especially fine, with stingingly sharp, original lines, deftly written.

Her relationship with her traditional mum is covered with both frankness and strong jokes, while Western images of her homeland are teasingly mocked. Off her specialist subject, she’s a decent enough comic, but on it, her set becomes enriched like so much Iranian uranium.

Closing the show was Frank Sanazi, the extravagantly offensive love-child of Adolf Hitler and Frank Sinatra. It may be a case of ‘ein volk, ein Reich, ein joke’ – but the gag is a good one, and flamboyantly executed.

The banter is full of Nazi-related puns, often tortured, often brilliantly obtuse, and while the rewritten song lyrics get a little repetitive, Sanazi livens things up with goosesteps and ‘heil’ salutes as nervous tics, Dr Strangelove-style. PC sensibilities, as you can tell, are gleefully abandoned for the sake of this good old-fashioned Knockabout act, with a slight pseudo-ironic twist. It’s a guilty pleasure, but a pleasure uber alles.