The goal was to improve seawater quality at Jumunjin harbor by enhancing the seawater exchange system. The researchers installed multi-outlets on the existing breakwater and tested four different cases using physical and numerical models. They found that the seawater exchange rate in the harbor was significantly increased with the new system. In one case, the total exchange rate was 48% due to dead zones, but in the other cases, the rates were improved by 15-19%.