If you have several islands to hunt and maybe some points on the shore line, some scouting is needed. Try and find where the birds are landing, whether it be for food or loafing. Divers tend to travel and raft in larger numbers than the puddle ducks, therefore larger numbers of decoys is a big help. If they are ringnecks, they will readily decoy to almost anything, especially reds and bluebill dekes. Try to keep the wind to one side or the other, rather than coming from your back, which would be perfered for mallards. Divers require a longer runway , and prefer it to be over water, thats why a crossing wind from behind will work best from a shore blind. Nothing beats being set up where the birds want to be, and that can change from day to day, and that's why scouting could be your answer. Good luck.
I'm not as good as I once was, but I'm as good once as I ever was.