[1] It is based on an idea of Bill Tilman, who had advocated a Three Peaks Challenge route without using motorised transport.
His doctor, Rob Haworth, with colleague Merfyn Jones developed the idea into a race.
They then sail across Liverpool Bay to Whitehaven on the coast of north-west England, where the runners cycle to Ennerdale and run over to Wasdale and up Scafell Pike and back.
Finally they sail round the Mulls of Galloway and Kintyre up Loch Linnhe to Fort William in Scotland where the runners scale Ben Nevis and return to the yacht.
Achieving a good enough start to gain the help of the Menai Strait tidal current after the Snowdon run can save several hours.