If you take clients in a boat with a motor, and accept payment for services then you need to have a captains license. Call wdfw they will inform you of anything you will need. I know when it comes to hunting and the use of boats some guys have gotten away with not having the captains license and other haven't. Better to be safe then sorry, just contact them. The Coast Guard has a say on what licenses you need as well which is why you would need the captains license if you were on federally navigable waters. Deer, bear, coyote and Turkey hunting you don't need to have anything if you are guiding on private ground. Fishing you need to have the states food fish or game fish guide license which is a fee, $300,000 in commercial liability insurance, captains license, first aid and cpr, business license, tax id number, drug test, twic card pass the coast guard 6pack test, pay fees, physical, and a few other things for the coast guard requirements for the Captains license which the state wants now. There are getting to be more and more things the state wants to be a guide anymore from what they wanted just 6 years ago.