The Great Explorers

Earth people information – Knowledge of Other Continents Prior to Contact: In the past there have been attempts to explore the ocean by the kingdom’s special ventures.
These ventures were funded by the old king in his early years for a 5 year period, where he provided renowned nobles the military and funds. Primitive ships were constructed utilizing wood collected from the central plains, mainly from oak trees based on the understanding of shipbuilding from the Kingdom Engineers. Prior experience in shipbuilding was based mostly on the ships built on the narrow shores of the central plain's rivers for the purposes of faster travelling. To easily navigate these territories, ships were smaller in size and did not contain masts. Engineers pursued similar designs in these ships. While ships had different designs and sizes, the average ship had the carrying capacity of about 10 – 15 people.
The ventures which took place mostly sailed off from the western waters, as it was the most easily accessible route with regards to access to a shoreline. While there have been several different starting points, it is important to note that all selected areas were based on sandy shorelines with little to no rocky terrain. This is to prevent any crashes from happening.
It was not unknown by the people of the kingdom that anyone sent to these missions were facing a dangerous challenge. The limited knowledge of the oceans have created questions of what lurks in the great beyond. Legends erupted that when a ship is out of sight for anyone beside its own crew, it is dragged under the sea, swallowed by a mythical creature underwater. Artwork related to this creature can be seen crafted by the people living in near the western waters. However, such stories are not only perceived to be true by the locals. The king himself ordered the ships to be designed in such a way to intimidate any sea creature. Examples of such designs include having a face carved on the front of the ship.
Another key precaution taken is that the rowing oars, while made completely of wood, have a sharp edge carved into them. This is to ensure the travelers can stab the creature if it were to attack the ship.
There is no clear indication on how many ventures took place in the 5-year time span. A significant portion of villagers living in western waters argue that the creature consumed them. Kingdom members living in the plains generally are more divided on the matter, a portion proposing they have died from the destruction of their ships. Only few believe these explorers might still be alive, most of them being the relatives of the ones who took the ventures.
The kingdom was not able to receive information on the whereabouts of the explorers. However, just off the coast of the southern sea, a single shipwreck was found recently by the desert people.
As such, most planet people don’t believe there is anything beyond their own continent.