As it got dark and the river was very peaceful and quiet we were able to convince the other 100 Peruvians resting quietly in their hammocks to start singing in unison "Siiiiiiiiiiiiiiilent night, Hooooooooooly night, aaaaaaall is calm, aaaaaaall is right..." all throughout the quiet night cruise into the wee hours of the morning. Even the cows joined in with the odd "Moo" right at the end of each chorus.