To get to Maraú from Salvador de Bahía you can take a flight to the Ilhéus or Porto Seguro airport and then take a bus or rent a car to get to the municipality.
Another option is to take a ferry from Salvador to Bom Despacho and then a bus to Camamu, where you can take a boat to reach the beaches of Maraú.
There are also transportation services from the Salvador airport to Maraú that can be hired in advance through travel agencies.
See also information on Salvador de Bahía y Porto Seguro.