Nexis Uni includes legal opinions and state and federal regulations, and the Government Publishing Office provides open access to the current Code of Federal Regulations, which govern the U.S.
The International Maritime Organization's International Regulations for Preventing Collisions at Sea, or COLREGS (find the text of the regulations in the Guide to the Collision Avoidance Rules ebook, below) are updated periodically as marine accidents expose gaps.
A regulation is a general statement issued by an agency, board, or commission that has the force and effect of law. Congress often grants agencies the authority to issue regulations. Sometimes Congress requires agencies to issue a regulation; sometimes Congress grants agencies the discretion to do so. Many laws passed by Congress give Federal agencies some flexibility in deciding how best to implement those laws. Federal regulations specify the details and requirements necessary to implement and to enforce legislation enacted by Congress.
From Office of Information and Regulatory Affairs FAQ (reginfo.gov; see link below)
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