Visitor,A problem for alot of us hunters.It is hard to answer your question
with out knowing a few things.Are you approaching from the same direction all the time?Is the wind in your favor?It seems he knows you are there either by sight, noise, or sense of smell.If the buck is hanging in the same area I would try to circle way around him instead of the straight on approach,if the wind is in your favor.Also another way would be if you spot him again just watch were he seems to want to go.You can then set up on him another time trying to ambush him.Again watch the wind direction.