Late-war Greek transfers found fewer Axis targets because Allied submarines already covered the Mediterranean's key approaches. A boat stationed off an enemy harbor could still report a sortie even when it could not obtain a torpedo shot. Malta's 10th Submarine Flotilla then waited where military and merchant convoys had to pass. Geography concentrated traffic and let a small number of submarines impose disproportionate losses and disruption. On that measure, the Malta campaign may have been the war's most successful submarine effort.
Notable Point · 1:17:43-1:19:28
Why Malta's 10th Submarine Flotilla was so effective
Malta's submarines exploited constrained Axis convoy routes, combining harbor surveillance with attacks against traffic forced through a narrow operating area.