30m is pretty standard with the chronograph watches, isn’t it? It’s not like you accidentally fall into the water on a daily basis. And if you do - I’d be more worried about the phone than the watch.
Plus if its 3bar, its easily good for 5meters and I'd like to see where you'll accidentally fall into water of 5 meters, even going swimming. Even at 10m more so. Approaching 30m?! Nah...
Any more pictures of the Longines big eye? Water resistance puts me off a bit