Federal and state tax returns for three years, monthly booking and revenue records, guide payroll, boat titles and trailer registrations, the dock lease, the state outfitter licence and every permit, each with written confirmation of whether it transfers to a new owner.
The licence file matters as much as the tax returns
A prudent buyer treats the seller's paper in two piles. The first proves the business exists and earns: tax returns as filed, monthly revenue by trip type, deposits already taken for next season, the guides' payroll and their licences, and a fixed-asset list with titles for each boat, motor and trailer. The second proves the buyer can operate it: the state outfitter licence and whether the state reissues it to a new owner or requires a fresh application with its own conditions; the dock or marina lease and the landlord's consent to assignment; any federal, state or tribal permits for the waters fished; and insurance.
Each item in the second pile should be answered in writing by the seller or the issuing authority, because a consular officer will ask how the buyer will lawfully carry paying guests on day one. Put the answers in the E-2 file next to the purchase agreement, and make any outstanding reissue a condition of closing, not a hope.