Unauthorized shelling of Coronado Islands and failure to follow orders
The PC-815 traveled to San Diego, which was to become her home port. She arrived there on June 2, and at the end of June was ordered to sea to join an anti-submarine training exercise. The exercise, held on June 28, ended early and Hubbard took the opportunity to order an impromptu gunnery exercise while anchored just off the Mexican territory of South Coronado Island to the south-west of San Diego. The Mexican government sent an official protest to the US Government, as no gunnery operations had been scheduled.
On June 30 a Board of Investigation was convened concerning PC-815 which concluded that Hubbard had disregarded orders, both by conducting gunnery practice and by anchoring in Mexican territorial waters without proper authority. His orders stated that the PC-815 was supposed to return after completing that day's training. Hubbard argued that his crew was inexperienced, it was foggy, and he was tired so he did not return to port as ordered. A month earlier in his after action report concerning the recent fiasco off Cape Lookout, he had described the same men as "experienced" and "highly skilled". Vice Admiral Fletcher, who both chaired the board and read the prior after action report, rated Hubbard "below average" and noted: "Consider this officer lacking in the essential qualities of judgement, leadership and cooperation. He acts without forethought as to probable results. He is believed to have been sincere in his efforts to make his ship efficient and ready. Not considered qualified for command or promotion at this time. Recommend duty on a large vessel where he can be properly supervised". Hubbard was relieved of command effective July 7, 1943.