Question 20 LB01 - Lifeboat Operator

The Correct Answer is A. **Explanation for A (Correct Option):** The hydrostatic release unit (HRU) is a critical component of the automatic release mechanism for a davit-launched or float-free liferaft system. Its primary function is to sense water pressure. If the ship sinks to a depth of approximately 2 to 4 meters (6.5 to 13 feet), the HRU is activated by the increasing water pressure. This activation automatically severs the weak link or cutting wire connecting the liferaft container to the ship's cradle or mounting point, allowing the liferaft container to float free and rise to the surface where it can then inflate. This ensures the raft is available even if the crew cannot manually release it before the ship goes down. **Explanation for Incorrect Options:** * **B) To inflate the raft automatically:** While liferafts do inflate automatically after floating free, the hydrostatic release (HRU) itself does not initiate the inflation. The inflation is initiated by the painter line pulling the firing head once the raft is released and the painter line has tensioned and broken the weak link *after* the HRU has already released the container from the sinking ship. * **C) To test the rafts hydrostatically:** Hydrostatic testing (using water pressure) is a separate process required for maintenance and certification of equipment like fire extinguishers or pressure vessels. The HRU's purpose is operational release, not maintenance testing of the raft material itself. * **D) None of the above:** This is incorrect because Option A accurately describes the HRU's primary function in float-free liferaft systems.