i take my dog stream fishing with me all the time and nothing frustrates me more when she runs ahead of me and starts trampling and splashing where im gonna fish in 5 min! but i do not care if she does so downstream where ive already fished. so i would like to teach her the command "behind" i do not need her on my side as if im wading waist deep water that really wouldnt work out. so i just need her to know that shes gotta be downstream of me instead of upstream. how would i go about teaching this? do i need to take her to the river and spend time doing it or can i do it at home?