Complex sentence: On 1 October, she was transferred to the II Squadron, where she served as the flagship, though she had informally served in this role since 17 September, as the previous flagship, the coastal defense ship, had been decommissioned.
Split into simpler sentences: On 1 October, she was transferred to the II Squadron, where she served as the flagship. She had informally served in this role since 17 September, as the previous flagship, the coastal defense ship, had been decommissioned.