1910 The YRC dug their way out of the bottom of Sunset Hole and into the bottom of Braithwaite Wife Hole, they later blocked this route because they considered it too dangerous. There was an accident and rescue from Sunset Hole, during which Boyd’s broken leg was set in plaster while underground on a rescue which took around 18 hours. Rat Hole was pushed as far as the top of the big pitch. A group were trapped by flooding in Eastwater for a short period.
1911 YRC members descended Swinsto Hole as far as the crawl beyond the first pitch. A further YRC attempt on Meregill, using “heavy wide ladders” rather than just ropes, got a small way beyond the third pitch.
1912 After five annual camps the YRC finally reached the bottom of Meregill Hole using “narrow Botterill ladders”. The Morgan brothers were the first to explore the entrance series of Dan-yr-Ogof (DYO). The Bristol Speleological Research Society was formed, and reformed after WWI as the University of Bristol Spelaeological Society (UBSS). The first descent of Disappointment Pot was made as far as what is now a duck. Moors, Crags and Caves of the High Peak and Neighbourhood by EA Baker was published.
1913 Rope ladder used on Mendip to descend Lamb Leer.
1914 The first party reached the bottom of the 12m (40ft) pitch in Swildons and explored to the top of the next pitch. Wookey Hole, Its caves and cave dwellers was published by Oxford University Press. YRC members made the first complete traverse of Crossover Passage in Meregill Hole, this was not done again for nearly 40 years.
1915 YRC explored upstream in Calf Holes.
1916 Whilst home on sick leave Harry Savory took some photographs in Wookey Hole. JW Puttrell explored Lathkill Head Cave.
1917 No reports of caving activity located.
1918 YRC explored Dismal Hill Cave.
1919 The University of Bristol Speological Society (UBSS) was founded. The UBSS Hut was erected near Burrington Combe and Reads Cavern was explored.