Not sure what the rules are for the state of DE but while daffy gone I see if I can help yea. If there anything like MI, you are allowed a fixed blind on public land but your last name and # number need to be clearly marked and the blind is yours to hunt from no matter what time you get there and most game warden's will remove you if you are in a blind that belongs to someone that owns it tring to hunt. If you want to hunt from the blind, find the number and give them a call, most guys are cool with it. If it is unmarked, it is on a first come , first serve. The rules about blinds should be in your waterfowl rules and regs book. I'll see if I can hunt for a link to help yea out.
Team Feather Finder
Hard Core Pro Staff
New Era Game Calls Pro Staff
If you can't ID it, don't shoot it!