Creates a White House Maritime Security Advisor and interagency Maritime Security Board, establishes a Maritime Security Trust Fund, and directs a package of studies, rulemakings, programs, and investments to rebuild U.S. shipbuilding, repair capacity, merchant fleet use, and the mariner workforce. It requires expanded planning and freight strategy to prioritize strategic sealift, updates legal definitions and foreign‑entity authorities, sets new Buy America and financing rules for ship construction, and modernizes merchant mariner credentialing systems (with a fiscal 2026 trust‑fund authorization).