A hybrid underwater glider(HDUG) is developed based on a folding propeller. The blades of the propeller can fold and unfold according to the motor work or not. When it stop spinning, the blades will come to a rest position. The hydrodynamic performance will vary with the position of the blades, thus the transit efficiency of the HDUG will also vary. So there must be an optimal transit efficiency for the propeller spinning position. Thus to investigate this problem, this paper presents a

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... approach characterizing the transit efficiency for different folding propeller spinning position of the HDUG. This paper employ first-principle analysis that concludes the effect of efficiency for spinning position of the blades. This result implies that the spinning position can effect the transit efficiency of a hybrid-driven underwater glider based on the mathematical model.