In a twist of fate, this bad luck allowed them to discover the lands that would become Las Guardas. Eager to get back to familiar waters, the crew simply marked of the location of the land for future exploration, and returned north. Similar to most large landmasses in the Southern Hemipshere at the time, the land was given the name "Terra Australis" ("Southern Land")
However, due to the fact navigation to and from the islands used the Southern Cross as a guide, a new name, "Terra Dos Guardas" ("Land of the Southern Cross," based on a name for the Southern Cross used by Portuguese explorer Joćo Faras) became the standard.
Things changed again when a new name for the Southern Cross constellation became popular in Portuguese: "Cruzeiro do Sul." With its name no longer tied to the constellation, the name underwent semantic bleaching. "Las Guardas" was now assumed to refer to the largest two islands, and "Terras Dos Guardas" (with a change to the plural in "Terra") being the name of the entire archipelago. From this, the name "Las Guardas" was applied to the main islands, and eventually also came to describe archipelago as a whole, with "Terra(s) Dos Guardas" falling out of use by the early 1800s
In Tagian, the name of the country is Tue Guardas (pronounced /twe gwardz/), with the Tagian plural feminine definite article "Tue" appended to "Guardas," which had come to refer to the islands themselves by the time the name was formalized, and thus was borrowed directly rather than translated from Portuguese.