rewolf wrote: Because the US don't even have any manned spacecraft any more

You are right. That makes the NASA approval irrelevant.
Making the russians both the first and ´last´ btw and I cherish my Gagarin homage.
The Vostok Amphibian thus holds the candle of the current most extreme up <-> down watch.
But... the crux of the thread is that th US Navy approved digital watches with elapsed time function as dive watch.