The base of Taranto was defended by 101 anti-aircraft guns and 193 machine-guns, and was usually protected against low-flying aircraft by barrage balloons, of which only 27 were in place on 11 November, as strong winds on 6 November had blown away 60 balloons. Capital ships were also supposed to be protected by anti-torpedo nets, but of netting was required for full protection, and only one-third of that was rigged before the attack due to a scheduled gunnery exercise. Moreover, these nets did not reach the bottom of the harbour, allowing the British torpedoes to clear them by about .