Oysters have been cultivated in Japan for a significant period of time, but the damage caused by typhoons has been a persistent problem. To address this issue, we studied the movement of Gros (oyster shell clumps attached to scallop) and hanging reams to identify the cause of typhoon-related damage. First, we constructed a Gro model and calculated the added mass coefficient and damping coefficient via a forced oscillation test. We also determined the drag coefficient from a drag test using the same model. Utilizing these coefficients as input parameters, we conducted a numerical analysis to study the behavior of the Gros and the hanging reams. In the numerical analysis, we subjected three hanging reams to waves, wind, and currents. We estimated the entanglement tendency of the hanging reams based on the distance between adjacent Gros. The results showed that the likelihood of entanglement of the hanging reams increased with a decrease in wave period for both regular and irregular waves. In addition, we discovered that the hanging reams’ entanglement was more likely when waves were incident in the direction where the chain was aligned.
