Keep calling Freeze out's update line for Swan numbers. When they get enough head over there, get on the causeway bank, cover up and get ready to have fun. Only need 3" B or BB shot, your shots will be 20 yards max (think my illegal swan last year). The swans hang out in a weeded area and take off right over the causeway. They are so big that they don't have much altitude by the time they get over you.
If you can get into the weeds between the Causeway and the road, where they hang out, that would be even better. (but you need a canoe or other non moterized boat)
Try to go on a week day too. Weekends have lots of jackasses who scare off swans, claim swans shot by others, ect...ect....
Also look to have some GREAT snow goose shooting too, they come in in flocks of THOUSANDS. And in between, there is decent duck pass shooting to occupy your time between swans and snows. I have a map of freeze out if you want it, I could try and PDF it and send it to ya.
Lord......let me be as good a hunter as my dog thinks I am....amen