4x4 trucks on an extremely bad sand road mostly every day from Barreirinhas, Leaving around 9 to 10 am sometimes a truck around 2pm, 1-2 hours, R$10.
Daily boatonly leaves when there are enough passengers from Barreirinhas via Mandacaru in the morning, 3-4 hours, R$10. return in the late afternoon.
You can also walk to Barreirinhas across the dunes, some 27 km, but you'd better arrange for someone to pick you up at the other end.
Walk to Mandacaru in about 1,5 hours. Start early to avoid the sun, and expect to get wet to your chest on high tide.
hire a fast boat for R$150-180, 45 minutes from Barreirinhas