The discussion centers on the 20 cm difference in sea level between the Pacific and Atlantic sides of the Panama Canal, with the Pacific side being higher. This discrepancy is attributed to various factors, including prevailing ocean currents and geographic features, rather than a continuous flow of water between the two oceans. The locks in the canal are designed to manage the elevation change over the mountainous terrain, preventing a direct flow that could equalize the levels. The conversation also touches on the role of temperature and density variations, as well as the influence of freshwater rivers on salinity levels. The participants debate the reasons for the persistent sea level difference, emphasizing that ongoing natural processes and geographic conditions contribute to the lack of equalization over time.