Galactus is a planet largely covered in deep, dangerous oceans. Crossing these oceans even in the present day can be a challenge, as travellers face storms, sea monsters, pirates, and a host of other worst-case scenarios. But many millennia ago, the folk of Galactus did not possess the technology needed to cross the oceans whatsoever.
In the early ages, folk of each continent lived very isolated lives. Only someareas, such as the Jade Sea, Gleigos, and Krobesh had any sort of travel between landmasses, and this was mostly thanks to coastal shelves which kept the waters relatively shallow and danger-free. Many folk had no idea that the rest of the world existed; it was simply endless ocean beyond the coasts of their homes. This meant that cultures developed in their own ways and had their own languages, traditions, and races. The only common thread was the deities, but the immortals did not reveal to the mortal folk thatother cultures beyond their own might exist.
Eventually, however, a particularly restless birdfolk found their way, by accident or with careful analysis of the windstreams, across the ocean to another continent. This opened up rudimentary communications between continents and cultures, but the birdfolk were often unreliable and could not bring other folk with them over the oceans.
The folk of Krobesh began to work on their ships in an effort to find a way to cross the ocean. Already used to nautical travel and the handling of boats, they simply needed to find a way to keep their craft afloat past the coastal shelf and across the open waters. Previous attempts were unsuccessful, as the small, light craft were only designed for the calmer tropical waters between the islands. After much trial and error, and many decades of research and development, a ship was finally built which could withstand heavy waves and winds and the storms of the oceans.
This first ship set off across the ocean, and made landfall on Ephora, the closest new continent. From here, the knowledge and design of this ocean-faring vessel spread quickly, and soon many cities were building their own ships.
The world slowly became connected across the vast waters that split it apart thanks to the ingenuity and perseverance of the Krobeshian folk. Other technologies, crops, and folk themselves began to slowly make their way to other lands, uniting the folk of the world slowly but surely, and the initial peacetime between the folk of each landmass led to massive leaps in technology, from medicine to magic. Languages spread slowly, and eventually one common language was developed, borrowing words from many other tongues, to help folk communicate with one another.
The ability to cross oceans on ships was one of thelast major unifying events in Galactus, and although the world has seen much peace, tensions still arise between kingdoms, whether neighbors or far from one another, brought on in many cases by the still vastly different cultures of Galactus.