As a cryptic marine species, G. watsoni is confined to shallow, intertidal areas that provide much shelter and refuge from predators and harsh conditions. The seastar was observed primarily upon the reef crest in amongst coral rubble and rocks.  Many asteroids are known to be negatively phototactic in which they avoid sources of light, which may be a behavioural response to avoid desiccation or predation (Kurihara 1998). G. watsoni was only located by overturning large pieces of coral where it was often found to be adhered to small cervices in dark, moist areas. It is likely that the preferred microhabitats of G. watsoni are small, dark and cryptic niches on rocks and coral in which they can effectively avoid predation, desiccation and capture prey.