There is a limit to the lifetime of these features: Europa's surface is relatively young, having been resurfaced by currently unknown processes some 50 million years ago.
And a 50mph speed limit is in place on much of the M4 in south Wales due to surface spray, while Environment Agency Wales has five flood warnings in place.
Even when the sharks are found closer to the ocean surface, they spend their time in the cool-temperature, plankton-rich waters that limit underwater visibility and make diving difficult.