The United States Coast Guard (USCG) is responsible for maintaining the safety and public accessibility of U.S. waterways. This includes promulgating the standards and licenses for the crews of all river and maritime vehicles, including pilots. While there are many additional specific subrequirements including a written exam, the basic qualification to become a riverboat pilot is a three-year apprenticeship on a similar boat with at least one year of experience on the waterways where you plan to work.
Determine the type and size of riverboat that you want to pilot. It is very important to make up your mind ahead of time; all riverboat pilot licenses are based on apprenticeships and experience with types and sizes of boats, and experience on a smaller boat will not count toward the experience requirements on a larger boat.
Join the crew of the type of riverboat you chose as a third mate. During your three-year apprenticeship you will need to work for at least 18 months on the deck of the boat or as a quartermaster. You are also required to have at least one year's experience working on the waterways where you will be piloting.
Contact the USCG National Maritime Center (NMC) when you have completed your apprenticeship and are ready to schedule your written exam for a first-class pilot's license.
Take and pass your written exam. You will thereby earn your first-class pilot's license and are ready to work as a riverboat captain.
It is possible to become an "acting as" boat pilot if you meet the requirements of the the local USCG Officer In Charge of Marine Inspection for round-trip experience on that local waterway.
Note that you must have a Certificate of Registration from the Director of Great Lakes Pilotage to serve as a boat pilot on the Great Lakes.