Vltava river ripples heard slowly crossfading from above to below water

With normal ears it is rather difficult to hear the river Vltava at Braník as traffic noise from the autobahn on the opposite bank continuously drowns out most smaller sounds including water ripples, rowing boats and kayaks. However at some spots mini waves breaking on stones at the river's edge are audible. This track was recorded simultaneously above (normal mics) and below water level (a hydrophone). At the start ripples and traffic noise are heard, which slowly crossfades into the gloopy, slopy underwater world, where the traffic is no longer audible.