The island's defenses were extremely strong: heavy coastal batteries on the western and southern coasts defended both the island and the Western Scheldt Estuary, and the coastline had been strongly fortified against amphibious assaults.
Øens forsvar var yderst stærkt: Tunge kystbatterier på vest- og sydkysten forsvarede såvel øen og Scheldemundingen, og kysten var blev kraftigt befæstet mod anfibieangreb.