A full moon, partial cloud, and calm weather gave aircraft unusually favourable conditions for finding and attacking a defended harbour at night. The Sunderland's overflight supplied final confirmation that the target ships had not sailed. Italian sound-detection equipment found the aircraft and prompted defensive fire even though crews could not see it clearly. One account says that shells fell in the town, after which anti-aircraft crews became more cautious about firing without a definite target.
Notable Point · 8:30-11:35
A Sunderland gives the final confirmation
A dusk Sunderland overflight confirmed the battleships remained in harbour while the weather still favoured a night attack.