Sport Fish Restoration and Recreational Boating Safety Act of 2021 This bill provides support for aquatic conservation (e.g., coastal wetlands and fisheries), boating safety, and boating infrastructure. For example, the bill reauthorizes through FY2026 and revises the Sport Fish Restoration and Boating Trust Fund, which provides funding for several things, including fisheries conservation and management, water and boating infrastructure, and recreational boating safety. In addition, it revises the Federal Aid to Wildlife Restoration Fund, which supports wildlife restoration, conservation, and hunter education and safety programs. The bill also requires the Government Accountability Office (GAO) to report on (1) the increasing use of nonmotorized vessels and their impacts on motorized and nonmotorized vessel access, (2) user conflicts at waterway access points, (3) the use of Sport Fish Restoration Program funds to improve nonmotorized vessel access and the reasons for providing such access, and (4) the use of Recreational Boating Safety Program funds for nonmotorized boating safety programs. The GAO must also consult with the Sport Fishing and Boating Partnership Council and the National Boating Safety Advisory Council on study design, scope, and priorities for the report.