Scuba diver ornament

Hi guys,

I remember when I was a kid seeing fish tank ornaments of divers, and
the used to continually float and then sink, with bubbles coming out
of them. I can't find them anywhere on eBay. Does anyone know where
I can get these, preferrably in Australia, but any will do.

Is my oscar likely to break such an ornament when he gets bigger?

Thanks.