Moreton Bay is filled with sandbanks from sand supplied via littoral drift along the coast of Moreton Island. The field of sandbanks extends across the entrance to Moreton Bay and evolved after sea level reached its present position, about 6,500 years ago after the last ice age Between Tangalooma and Skirmish Point on Bribie Island are the Middle Banks, Central Banks and Western Banks. From north of Moreton Island towards Caloundra are the Yulle Road, Spitfire Bank, and the Salamander Bank, amongst others.