Traveling to Tienne Del Mar
As there is no airport on Santo Antão, you will have to fly to Césaria Évora International Airport (VXE) on São Vicente and take a ferry.
With TAP Air Portugal you can fly from Brussels Airport or Amsterdam Schiphol to São Vicente with a transfer in Lisbon.
With TUI fly Netherlands you can fly directly (6 hours) from Amsterdam to São Vicente.
You can also fly to Boa Vista or Sal with TUI fly Belgium. From here you can fly to São Vicente or take a ferry to São Nicolau and a second one to São Vicente.