Sounds like some yahoos out in pursuit of a Darwin award. Everyone was OK, they got the boat to shore, and the guide and passengers should have learned a lesson or two. Not sure what other details there are that are important, or that should be shared publicly, other than, "Don't be this trip."
Rig to flip, dress to swim.
Nothing in the world is more yielding and gentle than water. Yet it has no equal for conquering the resistant and tough. The flexible can overcome the unbending; the soft can overcome the hard. - Lao Tse