Booking in advance is advisable, but not necessary.
Booking for multi-boat trips should be  one week in advance to accommodate your group with the best guides available.

I reserve the right to
cancel a trip due to
unsafe river conditions or other circumstances
beyond my control.  If canceled, I will refund your money in full, or
apply  it to another agreed upon date.

A 50% deposit is
required to confirm
reservations of more than 7 days in advance.  Final payment is due on the day of the trip. Cash, check, money orders, & travelers checks are all accepted. No plastic.