With that type of Smartweed growth out into 4' of water, there will be plenty of cover. Holy smokes! If my smartweed does that, I won't have a pond left. lol Most all the smartweed on my place lives in wet environments, but not actually out in the water unless your talking up to 6 inches deep. Some actually grows away from the water near the house. I wonder if there is a dryer version (like mine) and a wet version (like your uncles)? I also wonder if your uncle's plants are actually rooted on the bottom or if they are growing from the bank and merely floating mats.
