Although fossil fuels are the world's most abundant, economical, and reliable way for energy production, long-lasting usage, would cause serious issues and it is well established in scientific circles as a serious event. On the other hand, renewable energies play a key role as a substitute for energy production. The environmental issues and depletion of fossil fuels have paved opportunities to electric and hybrid vehicles, which use renewable resources, especially in transportation. This study examines solar power importance for energy system of an unmanned surface vehicle titled Morvarid, which is expected to do the bathymetry tasks autonomously. Before description major parts of Morvarid's energy system, the most important and related studies are reviewed. This is followed by selecting the most suitable components for Morvarid's energy system by numerical examination and modeling. A Plug-in hybrid management system with an 8 KWh capacity lithium-ion battery was proposed. The PV array area was modeled for the whole year and resulted that an array with 8 m(2) surface is the best option. The last section contains power management reliability and energy safety of the boat by experimental tests. The experimental test at Chitgar-lake revealed that the Morvarid's power generating system, which uses sun tracker, can produce about 5.8 KWh energy per day. The proposed energy management system optimizes the available energy usage to enable the boat to do its tasks up to 7 h per day during three cloudy days without charging. When using energy just for daily tasks, the boat does not even need plug-in charge at sunny days. (C) 2018 Elsevier Ltd. All rights reserved.