I'm an ex-geologist who now operates a caving/abseiling/rock climbing/photography adventure tour near Waitomo Caves, New Zealand.
Photography, and cave photography in particular, has long been a hobby of mine, starting over 20 years ago when I got a secondhand Pentax ME Super for my 21st birthday!
It's something I have incorporated into my tours, which were in fact my justification to buy a digital SLR and revive my interest in underground photography!