The best thing I can think to say about Donkey Punch is that it does exactly what it sets out to do, and does so with remorseless effectiveness. You pretty much know in advance what you’re in for, and that’s precisely what’s delivered: a shocker about what happens when some northern lasses meet some posh blokes on holiday in Spain, and take them up on their offer of going out to sea.

Anyone who’s heard a sea shanty could tell our heroines that they’re unlikely to be due a pleasant time. And I had the misfortune to study the godawful poem Peter Grimes for A level English, which is all about what happens when a salty seadog takes a series of handsome young men off the shore and returns without them. The canon is against our heroines, basically, so it’s no surprise that what follows is nasty.

The fate that befalls the women is a very modern sort of nasty, which is no surprise since this film is made under the Warp X umbrella, one of eight low budget features they’re making in the wake of the modest success of their first experiment in film, the Shane Meadows feature Dead Man’s Shoes. The role models for Warp X include Oz shocker Wolf Creek, and to some extent this is an aquatic variation on the theme.

The film is a morality tale of sorts, though one that’s already upset the Daily Mail. Our plucky Leeds ladies are wooed onto the boat by public school smoothies, plied with drugs, and what follows has a sick inevitability about it. Young people being up for sex is all well and good, but there’s a twisted laddishness at work that leads to one of the women being killed as the result of one of the guys trying to live out an urban myth, the one referred to in the film’s title.

The thing with corpses is, it’s hard to stop at one when you’re on a roll. And what follows is a textbook example of plotting that maximises the potential for conflict between every pairing of characters on board. It’s understandable that there’s tension between the guys about what to do now that one of their number is a killer, but even the two remaining women are split by their different understandings and objectives.

There are no great surprises here other than the ones you’d expect of a well executed film of this sort. It’s pacy, well performed and edited, and has a strong score, as you’d hope from Warp, up till now known for their music rather than their films.

I hope this film does well commercially, and see no reason to think otherwise. It’s not very ambitious, but it succeeds in achieving its aims, and if the Warp X slate can do that across the board then maybe it’ll pave the way for more films in the future. And if some of them can be as adventurous as the Warp musical roster, which includes Aphex Twin and Battles, then I’d be very happy. As it is, the musical equivalent of Donkey Punch would be a compilation of indie anthems by laddish bands; a few good hooks but nothing truly distinctive.