I have ben huntin since I was 8. I was always told,(& I agree), to never shoot a bird on the water. (Sportsmsns Ethics). My father was a market gunner, back in the 30's & 40's, then again after WW2. They did a lot of things that wernt exactly kosher, but at the time, it seemed ok.
My son has just terned 9. Took him huntin the last two days of waterfowl season, (it goes out during deer{gun} season then comes back in) He shot a lot and was getting discoragde. We had a singel come in, We let him shoot, befor he could get on the bird, it was on the water. I told him to take him. He did. You've never seen a happier boy.
I have taught him proper hunting ethics. And he knowes them. In my opinion, in some cases, it's ok.
Sorry if some people don't agree.