The paper proposes an innovative solution to transport workers of offshore oil production platforms from the coast to their units, which operate at the Pre-Salt exploration, 300 km from the coast. A passenger submarine concept design was developed, justified by the range of practical obstacles observed in the current modes of transportation, helicopters and supply boats. Requirements like operational depth (100 m), passenger capacity (250 people), and cruising speed (minimum 13.4 knots) are defined, based on estimates. Firstly, it seeks the adoption of air-independent propulsion (AIP) systems, by fuel cells (PEMFC). However, the work progress leads to an entire electric propulsion system. The internal arrangement is elaborated, regarding passenger comfort, structural constraints, allocation of batteries and ballast tanks. Then, after a hydrodynamic hull optimization, by Computational Fluid Dynamics analysis, we provide a final configuration with 100-m length and 9.7-m diameter, operational speed of 16 kt, and autonomy of 26 hours.