Which situation is least likely to result in an inspection by foreign authorities?

The situation in which a ship visits a port for the first time is least likely to result in an inspection by foreign authorities because first-time visits are generally part of routine port operations, and customs and port authorities may not have specific prior records or concerns regarding that ship. In many cases, first-time visits can trigger a standard procedure that is more focused on welcoming the ship and ensuring compliance with port regulations rather than conducting detailed inspections.

In contrast, the other situations imply potential concerns that may prompt scrutiny. For instance, if a ship's station license cannot be produced, it raises immediate compliance issues that authorities need to address. Observing operational irregularities suggests that there could be underlying safety or regulatory problems, prompting a thorough inspection. Likewise, the discovery of inoperative compulsory equipment indicates non-compliance with safety regulations, which would likely trigger an inspection to ensure the safety of the vessel and its crew. Hence, these scenarios present clearer motivations for foreign authorities to conduct inspections compared to the scenario involving a first-time port visit.