In this paper, we compare the performances of geographic DTN (Delay/Disruption-Tolerant Network) routing algorithms through simulation experiments. We compare message delivery times in five geographic DTN routing algorithms -- Random, Nearest, Farthest, Distant and AOD (Angle Of Deviation) -- while varying the number of mobile agents on the field and the capacity of wireless communication. Our finding includes that AOD algorithm, which prioritizes message loading and unloading according to the deviation of node's mobility vector and message's destination vector, outperforms other four geographic DTN routing algorithms.