It has been suggested that renewable energy sources be considered as replacements or blending stocks for middle-distillate ground transportation and marine fuels. It is vital for the operational considerations of these fuels to investigate the many positives and negatives that this use could prompt. Unlike air environments, water environments also have a pH factor that has to be considered. Most U.S. Navy shipboard fuel tanks compensate for diminishing fuel by the addition of seawater to the fuel tank. It was found that this practice would lead to fuel instability problems such as filter plugging and potentially other serious engine damage.