I have a different take on this as the majority of you do. As a blind owner/builder, I feel that it is my place to hunt, public or not. If I am not at the blind and you get in it, stay and enjoy it if I don't show up. If I do, I have the right to ask you to leave. If you refuse, I will not get any ego in the way, although sometimes I really want to. I sometimes will allow the "guests" to stay if there is room, but if I brought my own guests, I will ask you nicely to leave. Normally, the process is smooth but sometimes, arrogance gets in the way. When that happens, I will just back away and explain that I will simply keep you and your group from having any success. I will park my rig about 100 or so yards out of your way and make sure that any duck that comes near you will not want to work your spread.
If you pull that public lake BS on me, I will reply that those decoys your using are on public water, and I have the right to use them. See, it works both ways. Listen guys, for those of us who scout out an area, buy the material, and put in the many hard labor hours to build the blind, you as ethical hunters should IMO, respect that we, the owners, had 100% involvement in cost and construction, and you had nothing invested. So for you to claim it is fair to enact squatters rights because of public domain is just wrong. The issue is of ethics, being honorable sportsmen, and not letting any ego preclude good judgment.
I want everyone to have as much success as possible while hunting. Sometimes, I am late to my blind for unforeseen reasons. If I do not show up, because it is on public water, please use it, but take care of it. I hope you have a great hunt. If I show up and ask you to leave, please show me respect and honor the fact that it was my fruits that bought and built it. If those of you reading this disagree with how I feel and handle this type of situation, then so be it. Don't be a jerk when I ask you to leave and I won't be a jerk by ruining your hunt. If there is room and I want to invite you to stay, that is my call. If you want a blind to hunt out of, go scout out a place and build one as long as it is not on top of someone else's blind.
I also understand that someone can and has vandalized my blind so it is unuseable for even me because I asked them to leave. I know who it was that did it as well. But because I am ethical and promote good sportsmanship, I simply assume that risk and will elect to rebuild it again. I have the time and the money. My blind(s) have been in the same area I hunt for over 25 years and the locals know who owns them. Out of mutual respect, we do not hunt other people's blinds in my area unless we call in advance and find out the schedule of that blinds use and gain permission from the owner. That takes the surprise out of the equation. You are not helping yourself by using someones blind without prior permission. It would be better to find out the owner and talk to him about his blind. Find out if he would even consider allowing you to use it when he is not there. You might be surprised in what happens. More than likely, the two of you will strike up a lot of good hunting stories and find some commonalities between you. It may even become a lasting friendship simply because you made the effort to be ethical in the beginning with him.
Curl