Because of Silkie fluff they really can't handle their feathers getting soaked. A normal feathered chicken can sometimes float/swim in a shallow pond or kiddie pool but Silkies don't have that kind of feather protection. I am so desperately sorry your roo is gone. It's so horrible to think how helpless he was feeling and how tired he got struggling in the water - oh I hurt! Chickens aren't ducks - an open/filled pond can be covered w/a plywood plank or even pin-clip a tarp over and around it. Not seeing where they're going is a Silkie myth I'm convinced. Mine have had a lot of fluff and see predators, etc, no problem. But chickens spook at noises, shadows, etc, and the roo might've startled and just jumped the wrong way and couldn't get out. I have an Ameraucana that's always shrieking at flapping tarp, shadows from overhead aircraft, the sliding door opening or closing, a dog bark next door, etc. and we'll see her jump several feet in the air when startled. At least she can fly to get out of a situation but Silkies can't fly - they jump high but they can't fly.