One of two climbers to attempt an ascent live on television has recounted how his preparations have been dogged by bad weather and angry seabirds.
Dave MacLeod and Tim Emmett will tackle a new route on Sron Ulladale, an overhanging cliff on Harris.
The climb on 28 August will be filmed in high definition (HD) and broadcast on BBC Two Scotland and BBC HD Channel.
Blogging on his website, Lochaber-based Mr MacLeod has told of battles with the weather and bile-spitting fulmars.
The professional climber and his team encountered the seabirds while tackling sea cliffs on Orkney in June.
Mr MacLeod said he had "grim yellow slime" running down his neck while another of party was splattered with bile twice.
Fulmars spit a foul-smelling oil when they feel threatened, or to defend nests.
Last month, Mr MacLeod headed over to Harris to check out potential routes on Sron Ulladale which the climbers can ascend within six hours.
After two days of torrential rain, he attempted to scale the cliff only to find the break in the weather was a brief lull in a storm and he had to turn back.
He has been training on a climbing board at home, but plans a further trip to the Western Isles.
Triple Echo - which produces BBC Scotland's Adventure Show - said the Sron Ulladale climb will be a world first in terms of the technology used during the outside broadcast.
In February, Mr MacLeod and fellow climber Andy Turner recreated the most famous series of ascents in Scottish winter climbing, on Ben Nevis.
The pair retraced Jimmy Marshall and Robin Smith's first ascents of six routes in winter conditions made in a week 50 years ago.
Mr Emmett is an extreme sports athlete and climber.
Permission for this summer's programme was granted on the basis that the producers agreed a "leave-no-trace" commitment to protect the fragile local environment.
Most of the equipment will be flown in to prevent any erosion to the mountain trails and rare plant life.
Triple Echo said it was working closely with the North Harris Trust.
Dougie Vipond, who will present the broadcast, said the show could be "one of the most inspiring films ever produced of climbers in action".
Five other climbs made by the pair will feature during the programme.