 The islands are granite inselbergs up to 100m above sea level, and some are capped with calcarenite, a rock type of aeolian origin as windblown dunes.The islands feature precipitous cliffs to 75m tall, deep overhangs, sea caves, crevasses, talus slopes and summit platforms.The larger islands have some soil development and mostly support low shrubland communities dominated by nitre bush ("Nitraria billardierei"), gallweed ("Zygophyllum apiculatum"), saltbush ("Atriplex paludosa"), grey saltbush ("A. cinerea") and a daisy bush ("Olearia ramulosa")…

The islands are largely undisturbed because of the difficulty of access from the sea; Topgallant island contains some infestations of African boxthorn and common ice plant…

The registered islands in this group, namely Waldegrave Islands (sic), Topgallant Islands, Ward Islands and Pearson Islands, are true inselbergs or island mountains, rising abruptly to a maximum of 240m above sea level from the eastern section of the Great Australian Bight.