- YAPATE Inlet
- Really
important phreatic level from Knossos leading north (1988/89).
[Picture]
- YATMP
- Yet Another 20m Pitch in Drunk and Stupid (1989)
- Yoda
- Mazey bit in Bladerunner (1992)
- Yorkshire Holiday
- Final 40cm wide rift in Chaos Series (1996)
- Yorkshire Pudding
- Squeeze just inside 161e entrance passage (1996) (named when the Dour
Yorkshireman had to be excavated from it during the initial exploration)