If you don't already know the meaning of a "donkey punch", you certainly will by the blood-soaked conclusion of Olly Blackburn's lurid, sex and drug-fuelled thriller.

A sweaty orgy aboard a luxury yacht, where the titular act of kinky experimentation takes place, leaves little to the overheated imagination as Blackburn's camera ogles the writhing flesh of his attractive cast.

Once the punch is performed - to the back of the neck of one unsuspecting young lady - her death sparks a formulaic and increasingly brutal battle of the sexes, which proves beyond doubt, the female of the species is just as deadly as the male.

The cramped confines of the yacht provide an effectively claustrophobic setting for the film as it sails into similarly choppy waters as Dead Calm.

Unfortunately, logic tumbles overboard as director Blackburn and co-writer David Bloom struggle to sustain the air of paranoia while killing off cast at regular intervals.

At least the scantily clad stars make beautiful corpses and judging by the woodenness of some performances, their lifeless bodies should drift out to sea without any fuss.

Yorkshire lasses Kim (Jaime Winstone) and Lisa (Sian Breckin) slap on the sun protection factor 15 in Mallorca, hoping to cheer up pal Tammi (Nichola Burley) who has just split with her no-good boyfriend.

The fun-loving gals tour the local bars where they meet likely London lads Bluey (Tom Burke), Josh (Julian Morris) and Marcus (Jay Taylor).

When the boys reveal they all crew on a nearby yacht, the girls excitedly agree to continue the party back on board, where sensitive head crewman Sean (Robert Boulter) is waiting to catch Tammi's tearful eye.
A sex romp between five of the group ends in tragedy when Josh is goaded into donkey punching Lisa.

"The best thing for everyone is if we say she fell overboard. No body, no case," suggests Marcus, trying to take charge of the situation, but Kim and Tammi aren't willing to go along with the cover-up.

Donkey Punch doesn't spend any time developing the characters before plunging them into a moral quagmire from which senseless slaughter is apparently the only means of escape.

Hairstyles are all that differentiate one empty-headed girl from another while Burke's portrayal of the ringleader of this circus is pure caricature.

The plot treads water in the middle act before hell breaks loose for the gory finale.

The characters' stupidity is exemplified when Kim and Tammi are locked inside a cabin and decide to break out by smashing through a pane of toughened glass.

Having walloped the partition to within a breath of shattering, Tammi decides to finish the job by running through the glass, setting up the inevitable, stomach-churning close-up of a sliver embedded in her knee.
And she wonders why her boyfriend broke up with her?

Film rating 2 out of 5

Watch the trailer here