I got what you thought was a clever tip, pretty feeble---You may think you
know the concept but density has nothing to do with it---Ships are "pretty
dense" and they float; same principle applies as to why a pound of feathers
floats and a one pound cement brick sinks. If you have another tip as to
why I'd be glad to see it. In the meantime, if you want to see dense look
in the mirror.
BTW, Here's a tip for you--ever try to hold a beach ball under water?
Cement is heavier. You'd have to be dense to miss that.