You are underway in fog and hear a fog signal of two prolonged blasts on your starboard quarter. What should your next action be?

When you hear a fog signal of two prolonged blasts on your starboard quarter, the correct action is to hold your course and speed. This signal indicates that there is another vessel in proximity that is also navigating in conditions of restricted visibility, and it signals its intention to maintain its course while you are approaching from the right side.

Maintaining your course and speed helps to ensure that both vessels have predictable movements. This can significantly enhance safety by reducing the risk of collision, as it allows you to assess the other vessel's movements and react accordingly. Additionally, this approach follows the navigation rules established for fog situations, which emphasize the importance of predictable actions from vessels to prevent accidents.

Changing course to the left or right may confuse other vessels and could potentially lead to a collision if their intentions are not clearly understood. Stopping your vessel could also create a hazard as it may not allow for proper maneuvering, especially if other vessels are on a collision course. Therefore, the best and safest response in this situation is to hold your course and speed while remaining vigilant.