What is a defining characteristic of the ARA San Juan's last mission?

The ARA San Juan's last mission is notably characterized by significant electrical issues that hampered its operations. These technical difficulties played a crucial role in the mission's challenges, affecting communication and navigation, and ultimately contributing to the tragic loss of the submarine. The electrical problems were so severe that they compromised the crew's ability to manage the submarine effectively, leading to critical situations that could not be mitigated.

In the context of this question, the emphasis on electrical issues highlights the importance of technical reliability in underwater missions and the potential consequences when such systems fail. Understanding these factors is crucial for recognizing the complexities involved in undersea operations and the need for rigorous maintenance and checks in naval vessels.