Defeating the RAF would not solve Operation Sea Lion

How could Germany have carried out Operation Sea Lion if the Luftwaffe defeated the RAF?

The premise is insufficient: Germany would need a durable definition of RAF defeat and still had no convincing answer to Royal Navy intervention, especially at night.

A Sea Lion scenario first has to define how completely and for how long the RAF has been defeated. Local air superiority would leave aircraft production and forces farther north as separate problems. British fighters could pull back beyond effective German range and still return to contest the invasion. Even a stronger German air victory would leave the crossing vulnerable to Royal Navy attacks at night. Battleships, cruisers, and destroyers could accept heavy losses to destroy the invasion shipping and strand troops ashore. German naval losses in Norway would have to be removed from the scenario, and even the intact fleet lacked the right preparation and vessels for the invasion. Canal and river craft were particularly poor substitutes for suitable amphibious shipping.