Why the East Mole became an evacuation lifeline

The main harbour's seven dock basins had been blocked by air attack, leaving only two principal embarkation points in Dunkirk itself. The local naval commander had reduced the blockage by ordering merchant and French naval craft to sea when the attacks began. The excerpt emphasizes the East Mole's great length, very narrow usable width, and survival despite repeated attention from German aircraft and artillery. Most troops embarked through the harbour had to pass along this vulnerable structure. The evacuation depended on resilient harbour infrastructure as much as on the famous image of boats waiting offshore. Shallow and obstructed coastal water then required small craft to ferry troops from beaches to deeper-draught ships lying farther out.