A rapid advance dependent on local food supplies

Sea Lion's supply assumptions differed from those associated with Overlord because the Germans expected a short operation. They planned to obtain food from stores and other resources along the route. That expectation assumed the inhabitants would leave usable supplies behind. The intended advance toward London was measured in days, with capable commanders on both sides, including Montgomery in the British defense. Any sustained resistance or loss of access to local food would therefore challenge the timetable on which the plan relied.