The act of engaging in sexual relations with a woman who has a large, dark and cavernous vagina. This act of extreme
desperation and bravery is usually reserved for men who have gone
more than three weeks without
getting laid, and who are willing to submerge themselves (without safety equipment and/or flashlights) without preparation into a vagina in which many enter and few return.
Examples:
"Koumi was one of the ballsiest
spelunkers I have ever seen: he used to fuck XXXXXX without a condom or a GPS system"
"Guys, we lost one of our own today. I just got word that Andrew Tha Owner" died on a spelunking trip
yesterday. He was in Wunsch's Cave when he sprained his ankle, and was unable to escape. He
eventually ran out of air, and died."