@Block builder this one's thanks to you, you got me thinking about parachutes... They're more like mini helicopters to be fair (and couldn't manage a parachuting dog) but hopefully you get the idea...
Their weight is a little too unbalanced. In order for them to float, they have to stay upright. But they keep going sideways movement or upsidedown here.
I have yet to try this one, but I like how you contained the water inside the building by only using metal blocks outside.
@Frenzies that's true, but somtime's you can do it and they float beautifully. Like you I'm not convinced this is the best configuration for floating. The most graceful I've seen was @richardfu 's Eagle level... Maybe it's worth trying to do something like that with them, it's not as if they actually look like parachutes at the moment!
