The present study conducted a comprehensive examination of the design and analysis of an offshore fish cage based on an existing fish cage known as ”shenlan.” The study began with a thorough site selection process, which resulted in the decision to position the fish cage around 20 kilometers from the massachusetts bay shore, at a water depth of 64.6 meters. To optimize the net design, computational fluid dynamics (cfd) simulations were conducted using the tdyn cfd+ht software. Finally, a seakeeping analysis was performed using the tdyn seafem software to assess the fish cage’s motions within acceptable limits.