True Great Circle
Ryu already had a perfect map of the region in his mind, he didn't need to go and double check. The problem was how he would set up anything. Doing it in advance was obviously impossible because that would require stepping into the beast's territory. Once he did so, it would have free reign to attack him as it pleased and by then, he would have to focus everything on surviving.
Of course, there was another path, and that was to focus all of his attention on closing the gap. But Ryu felt that it was impossible if he was also considering a time frame on top of everything else.
In the back of his mind, though, he was constantly thinking of just where the gap lay, and he believed that he had some understanding.