In reduced visibility a power-driven vessel under way gives which sound signal every 2 minutes?

In reduced visibility, a power-driven vessel underway is required to sound one prolonged blast followed by two short blasts every two minutes. This signal indicates its presence to other vessels in the area. The prolonged blast lasts about four to six seconds, while the short blasts last about one second each. This signaling helps to prevent collisions in situations where visibility is limited.