I asked your question on the British Cave Divers Group, and got this answer:
"The Darkness Beckons records an attempt at free-diving Buxton Water Sump in Peak Cavern in 1777. This is at the end of the show cave well beyond daylight so counts as a "sump dive" in your parlance. Standard equipment was in use in France, Switzerland and Austria towards the end of the 19th century."
Any opinions are personal.