From the Amsterdam Island DXpedition website
We have been assigned two operating sites on the north end of the island. One site, a shelter called Mataf, is located just northeast of the base. It is over 400 feet from the sea and the beach area has small cliffs, is rugged and rocky, and is exposed to the high sea. Having antennaâ€™s at the waterâ€™s edge is not really an option. We will use verticals for the low bands and 3-element Yagis for the high bands.