In a situation where vessels are on reciprocal courses and at risk of collision, which action is required?

When vessels are on reciprocal courses, they are moving toward each other, which places them at risk of collision. In such situations, maritime navigation rules (COLREGs) dictate the required actions to avoid collisions. The rule that applies here is that both vessels should alter course to starboard.

By both vessels altering course to starboard, they ensure that they pass each other on their respective port sides, which is a standard way to avoid collisions in these scenarios. This action minimizes any potential confusion, as it is a universally accepted maneuver in maritime navigation.

Other actions mentioned, such as maintaining speed or altering course to port, would not effectively mitigate the risk of collision when headings are directly opposed. Sounding horns is a warning signal, but it does not address the actual mechanics of avoiding a collision. Therefore, altering course to starboard is the necessary action to ensure a safe passage when vessels are on reciprocal courses.