Trigg Island is a small island off the coast of Perth’s Trigg neighborhood in Western Australia. It is a small rocky aeolianite limestone relic of Pleistocene dunes, best described as an outcrop than an island, and is characteristic of the Perth coast. Trigg Island is famous for its blue hole, which is located at the island’s southern tip. Four men nearly drowned in September 1931 when their boat capsized near the blue hole. Two brothers drowned in the blue hole in May 1947, and a nun named Sister Mary Chrysostom and her would-be rescuer Frederick Charles Floyd drowned later that year in July. The Trigg Island Surf Life Saving Club has a plaque honoring the deaths of the latter two. Since then, several more people have been rescued or died in or near the blue hole. These incidents were crucial in the creation of the Trigg Island Surf Life Saving Club.