We recently ran across a good forum discussion on this very topic on gCaptain.com. It points out that a 1983 Memorandum of Understanding between both agencies concluded that the USCG has final say on worker safety (concerning inspected vessels).

Specifically, “the Coast Guard is the dominant federal agency with the statutory authority to prescribe and enforce standards or regulations affecting the occupational safety and health of seamen aboard inspected vessels. Under the Vessel Inspection Laws of the United States, the Coast Guard has issued comprehensive standards and regulations concerning the working conditions of seamen aboard inspected vessels.”

However, “OSHA has the authority to require vessel owners to post a notice that informs employees of their right to complain about working conditions to the Coast Guard, OSHA, or the employer and to be free from retaliatory discrimination.”

The discrepancy in agency enforcement of safety explains why standards of enforcement between shore-based and offshore jobs are not uniform. For example, in 2008 the Coast Guard ruled that “no regulatory requirements were violated” in the case of an 18-year-old crewmember who was not wearing a safety harness when he fell to his death on a schooner. Had this accident occurred on a land job the employer might well have been in violation of OSHA standards but because it was on an inspected vessel the USCG had the final say.