Watch Scrapheap Challenge online: Episode 5 Jet Boat

The Challenge This week's challenge is to build jet-powered speed boats that are both agile and fast. The teams will be competing in a two-part Grand Prix – on jet boats! The race will start with a full-throttle dash up and down the lake and will be followed by the twists and turns of an off-shore obstacle course. Hairy Hogs Conn Kelly, Darrell Hanna and Alastair Nethercott are the Hairy Hogs from Northern Ireland. All members of the Provincewide Harley Owners Group, they are big blokes with bigger laughs who love their Harleys and spend much of their year touring around Europe on them. The Hogs are seriously hands-on and have had experience of most possible mechanical projects. They are rough 'n ready, rugby-playing, Guinness-loving men who are up for the challenge and in search of a 'good craic'. These guys are quietly confident they can't be beaten and should give even the most solid of Scrapheap teams a run for their money! Apparently, they're up for most things apart from a water challenge (ha!). Alan Pickard is the Hairy Hogs' expert as well as being one of the foremost jetskiers in the UK. He runs Jet Shed, the leading specialist workshop in this field in the UK. Previously seen on White Water Rider (series 4), he is a hands-on bodger and technician and previously held the speed record on a jetski – he is currently ranked number three in the UK. Team Ragbo Glynn Myers, Nick Mellor and Colin Bates all work at Smart Recycling, Glynn's plastics waste-recycling firm in Lancashire. Between them, they have worked on everything from factory equipment and heavy plant machinery to cars and bikes. This team are heavily into their bikes and two years ago Nick sold his house so he could buy a Triumph bike – he now lives in a caravan! There is a wide breadth of experience and knowledge in this team and the guys are confident they can deal with anything we throw at them! Glynn and Colin are larger than life in every respect, with 'Hippy Nicky' being slightly quieter – but he sees himself as their 'secret backbone'. Lots of northern humour, loads of energy and bags of banter – you won't be able to get a word in edgeways! Alex Wallis is Chief Engineer at Pursuit Dynamics and will be Team Ragbo's expert this week. His company specialises in pumps, fluid management and innovative marine propulsion systems using steam power. Alex is a mechanical engineer with a practical background, particularly in the bodging of various automotive matters and he's even built his own sail plane. The judge Michael McDowell works for Polaris UK as their technical man, on hand to answer any mechanical problems in the Polaris Jetski dealership chain. He also trains all sales outlets on the mechanical running and maintenance of Polaris Jetskis. He has been working for eight years in the field of maritime power units, impellers and jetskis. He also has an engineering background in motor mechanics, quad bikes, outboards and even pumps. When it comes to summarising what makes a good jetski, Michael can talk at length about all the key ingredients with consummate ease.

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