When might three short blasts also imply "I am backing up"?

The statement "I am backing up" is indicated by three short blasts of a horn, but this signal can vary based on the type of vessel and its context. Not all vessels are governed by the same signaling rules, and different types of vessels may have unique protocols.

For example, some larger vessels or those that may not be as maneuverable have specific requirements regarding how they indicate their movement to other boats. Therefore, the use of three short blasts to signify that a vessel is backing up is applicable to certain types of vessels, such as powerboats, commercial vessels, and others that operate under the International Regulations for Preventing Collisions at Sea (COLREGs).

Smaller boats, recreational vessels, and sailing vessels might have different signaling conventions. Hence, the use of three short blasts as a universal signal for backing up does not apply across all types, but rather to specific categories of vessels that recognize and utilize this signal consistently. Therefore, it is accurate to say that three short blasts imply "I am backing up" for some types of vessels given their operational context and requirements.