Humans have long been curious about the causes of tidal movements. Ancients viewed tides as akin to the natural breathing of the Earth, inhaling and exhaling, or attributed them to the action of supernatural, mystical forces. However, some Greek natural philosophers understood that tides were related to the movements of the moon and the sun. In China, awareness that the tides were affected by the waxing and waning of the moon existed early on, and by the 6th century, the geographical text "Shuijing Zhu" recorded that the tides changed according to the phases of the moon. Nevertheless, the exact origins and mechanisms that cause tides could not be clearly explained.

Cities situated along rivers and coastlines have periodically experienced flooding. Floods have had a massive impact on the growth and development, as well as the decline and fall, of cities. Humans have continuously strived to control and manage water to mitigate these effects. Maps and paintings of old cities can reveal the past topography and landscapes, the forces of nature, and the human footprints that stood against them.

Mudflats are areas where the sea appears and disappears due to the tidal movements of high and low tides. Heavy particles like sand carried by the sea accumulate on the shores of river estuaries, while smaller particles drift further out and settle in calm bays or along the coast, forming these flats.
Mudflats are rich in nutrients, supporting a diverse range of life. People have developed various tools to harvest different types of shellfish, fish, and octopus from these areas. Some tools originated from agricultural implements but were modified to suit the unique conditions of the mudflats.

Our ancestors began building boats early on to navigate rivers and seas. The initial boats were fashioned by hollowing out large logs, followed by the creation of rafts made by binding several logs together. While no boats from the Three Kingdoms period survive today, it is known that various types of boats were constructed for different purposes.
During the Goryeo and Joseon dynasties, a transport system was established to facilitate the movement of goods, and naval forces were set up for maritime defense. By the end of the Joseon period, the transport system was abolished, and naval production ceased as the navy was disbanded. Traditional fishing boats maintained their presence until the Japanese colonial period, but eventually disappeared with the introduction of Japanese-style fishing boats. The techniques and tools for building boats evolved, blending traditional and new methods, and coexisting in this transformed landscape.

Korea's rivers and seas are abundant fishing grounds inhabited by a variety of fish. People have crafted fishing tools suitable for the natural conditions and habits of the fish. In the shallow seas where tides ebb and flow, fish were trapped using wooden fences or stone walls. People also ventured out to sea in boats to catch fish.

Eohaedo is a painting that depicts various aquatic creatures. In China, a typical style was established during the Song Dynasty, and in Joseon (Korea), it became widely popular after the 18th century. The fish depicted in these paintings embody various wishes. Fish drawn paired or swimming in groups symbolized abundance and fertility, while creatures like carp, mandarin fish, turtles, and crabs were seen as symbols of successfully passing the civil service exams and ascending to official positions

During the lunar New Year, the residents of Daerim Village in Buan County on Wido Island perform a ritual at the shrine with great devotion and craft bamboo rafts by the seaside. These rafts are made from bamboo grass, silver grass, and reeds, and are equipped with masts and anchors. The villagers roam around the village performing ceremonies and gather by the seaside to conduct the Dragon King Festival. Once the tide comes in after the festival, the rafts are launched into the open sea. Each raft carries a scarecrow and various offerings to the Dragon King, embodying the villagers' profound hopes and prayers for abundance and safety as they drift into the distant sea.

Today, the salt we commonly consume is solar salt, made by sun-drying seawater. Before the advent of solar salt in the Korean Peninsula, salt was produced by boiling seawater, known as Ja-yeom. The methods for producing Ja-yeom varied by region, involving either directly boiling seawater or creating salt fields to boil the seawater collected therein. Salt fields were constructed by enclosing seawater with embankments or directly on the higher grounds of mudflats.