Question 3365 Deck General

The correct answer is C) working over water. According to Coast Guard regulations, a life preserver or buoyant work vest is required to be worn when a person is working over water on a mobile offshore drilling unit (MODU), as this poses a significant risk of falling into the water. The other answer choices, while potentially relevant to safety on a MODU, do not trigger the requirement for a life preserver or buoyant work vest. Working on the rig floor (A), operating line throwing equipment (B), or working on the pipe racks (D) do not necessarily involve working over water, and therefore do not require the use of a life preserver or buoyant work vest as per the regulations.