Tuléar is the hub of the Great Reef. North of Tuléar, there is little or no public transport after Mangily. With the exception of private planes, the northern hotels are all reached by private 4WD. Transfers can be arranged, but are expensive.
South of Tuléar, there are boat transfers to Anakao, which is a quick and wonderful way to arrive, but south of Anakao you need a private 4WD again, or lots of time.