The Italian fisheries industry is seeking to improve the energy efficiency of its vessels, instigated by the rising cost of diesel oil and decreasing catches. Saving energy has been the subject of research since the oil crises of the 1970s, leading to several studies aimed at improving vessel design with a view to reducing power requirements. In the framework of RITMARE (SP2_WP5_AZ3) Flagship Project funded by the Italian Ministry of University and Research, a new performance monitoring system for commercial fishing vessels (PeMoS) was set up in order to evaluate the energy performance of fishing vessels during working time. It consists in a Central Control Unit realized with a compact rugged industrial computer (NI CRio 9075) and interfaced to several instruments via analog interfaces (using NI 9219) or serial buses (using NI 9870). The CCU acquires, elaborates and stores energy parameters of vessel and it sends them to a FTP server as soon as a dedicated WiFi connection is available; the connectivity is allowed by a DLink 1160 AP connected over Ethernet to the CRio. The system also integrates data from the shipboard GPS and weather station. In the case it was uncomfortable to make a cabled connection between CCU and the serial instruments, some RF repeaters (Blizzard 868) have been predisposed. A client application for windows platforms has been realized to display to user an overview of the actual values acquired as well as the history graph or table of the last hour of acquisition. Moreover it allows to manage CCU settings and to send it maintenance commands. The system integrates The system has been tested in the Adriatic Sea on board of R/V “G. Dallaporta”, 810 kW engine power and LOA = 35.30 m.