The paper addresses the evaluation of wave energy absorption at a fishing pier in the town of Balneario Arroio do Silva, coastal south region of Brazil. This study considers the use of oscillating-water-column (OWC) converters composed by tubes tied to the pillars of the pier. In order to evaluate the wave energy extraction, the mathematical model of the OWC device for this specific application is obtained. First, wave equations and fluid mechanics theory are used to describe the physical behavior of the air inside the tube. Then the air flux is converted to mechanical torque using Wells turbine equations. The time-domain model is simulated using computational tools and taking into account the actual parameters and the specific wave regime at the fishing pier. The study shall support a future experimental implementation of OWC devices at the fishing pier. In addition, an energy efficiency analysis is developed, in order to reduce the consumption of electricity and energy waste at the fishing pier, and aiming at sustainability and rational use of the energy produced by the proposed OWC device.