What does one short blast by Vessel "A" indicate when two power-driven vessels are meeting?

When a power-driven vessel sounds one short blast while meeting another power-driven vessel, it indicates the intention to leave the other vessel on the starboard side. This signal is standardized under the International Regulations for Preventing Collisions at Sea (COLREGs), specifically in Rule 34, which addresses the sound signals used by vessels when navigating close to one another.

The significance of this one short blast is to communicate clearly and effectively the vessel's maneuvering intentions to avoid confusion and potential collisions. In this case, Vessel "A" is stating its intention to pass the other vessel while keeping it to the right, which aligns with the proper navigation practices to ensure safety while at sea.

In contrast, the other options do not accurately represent the meaning of one short blast. For instance, stating that the vessel intends to leave the other vessel on its port side or to alter course to port would be incorrect, as those intentions would require different sound signals according to COLREGs. Thus, it is essential to understand the specific sound signals and their meanings to navigate safely and effectively in waterways.