Current commercial Autonomous Underwater Vehicles (AUVs) are powered by conventional batteries. However, such technology has reached a point at which an increase of the endurance and range of operations would require increasing the size of existing AUV designs. Much attention has been paid to fuel cells as they have proven successfully installable in AUV prototypes and have shown good results regarding the increase of range and endurance of AUVs. Nevertheless, no commercial AUV powered by fuel cells has been made yet. In this work, the characteristics of well-known commercial AUVs have been studied using the Principal Components Analysis. Such study allows inferring the requirements and constraints for the implementation of fuel cells in commercial AUVs. Freedom in certain design parameters of both fuel cells and AUVs has been found. Regarding the necessity to store oxidant along with the fuel in underwater applications, a map of achieved energy densities by the combination of different means of storing hydrogen and oxygen has been obtained. Such map reveals the most benefiting combination of storage means for both reactants. Finally, a method for obtaining the initial design parameters of fuel cell powered AUVs is proposed.