100 to 150ft is plenty of room if your not running your motor. Drifting by at that range should not have been a problem at all. When someone decides to troll around you close in that's a completely different issue. Everyone likes to have as much of their own space as possible but sometimes that just doesn't happen. Wind direction, water depth, whatever brings people in close proximity to one another. To me the range you mentioned is plenty far apart especially since you were drifting and not powering through. There are guys that even if you gave them a half mile would have been kicking and screaming. Be courteous and in most situations two people will work out their differences. If the guy was hooked up and the fish was coming towards your boat, I'm sure you would have steered clear. Every situation is different and more so the people involved normally dictate what is acceptable and what's not.

Dakota