When we ask the USCG Prevention staff what is the proper action. They suggested call the USCG. Not the best for client relationship. No matter what state or local laws state, when on federal waters with a USCG issues license, you can not have illegal drugs on board.
My suggestion to any captain is to tell the client before you leave the dock, NO illegal drug. Leave them in the car. If found, trip in terminated at your cost.
If there is an accident or a boarding, it is not just the license, insurance may not cover an accident and you could loose your business.
As more states legalize marijuana, this will be a serious issue for all guides. As I tell our students; you are a business person first, minimizing your risk is a must.
Capt Gary Kulibert Explorers Guide Maritime Academy