The islands of the Indian Ocean are a varied collection, including many of the smallest territories and one of the largest island nations (Madagascar). Many hug the coastlines of continents; others must be sought out hundreds of miles from any other land.
The one thing they have in common was being affected by the tsunamis of Krakatoa in the 1880s, and on Boxing Day 2004, in both cases ranging from remarkable waves to inundation.
The subantarctic islands south of 45° latitude are categorized on this site as islands of the Southern Ocean, rather than islands of the Indian Ocean.