public land is public. nice of you to be sensitive; i wish more people were like you. but if you get there first, then the spot is yours. you could be nice and offer to let someone join you if they walk up afterwards, but just because someone was there yesterday or last week doesn't give them any more right than you today. if you get there and someone's already in the hole, tough luck--unless they offer you to hunt with them. personally i wouldn't get close enough to hear the offer because if you're close enough to hear them ask you something, then you're close enough to screw them up. (what they ask in that situation won't often be a nice question...) if your spot is occupied, you can very well set up in another spot, but whatever you do, don't a) walk through their dekes (or even within 200 yards of their dekes)--i know this sounds obvious, but people do it--or b) put your own spread out anywhere within 200 yards. it's better if you stay farther away, but in many states the standard law while waterfowling is that you must remain at LEAST 200 yards. if there's no other place the ducks want in, lie on the levee, pour a cup of coffee, and watch the hunters; you'll probably learn something. finally, if your friend showed you the spot last year, you should call him before you hunt it, just to have good manners. it's public, yes, and neither of you own it, but if it was shown to you, you should just say you're going there, and would he like to come along. that way he won't think you're stealing his spot. good luck--you're obviously a nice guy or you wouldn't be asking that question, so you'll be fine.