Rules of Three for Caving
By Val Hildreth-Werker
I've used this with lots of scouts:
cave in groups of at least three people.
tell three people where you're going and when you'll be out of the cave.
have three light sources
three points of contact on climbs
international emergency signal is what? Three of just about anything.
Three toots on a whistle. Three honks on a vehicle horn. Three giant x's made of rocks or snow.