Remember homo sapiens sapiens evolved to be the best terrestrial endurance hunter. In Africa stone age tribes still hunt this way, basically they'll chase/track an antelope (you read right, a GD antelope) until it collapses from exhaustion and heat stroke. But get this, not only are humans amazing on land, turns out the human body has something called a dive reflex enabling us to dive to depths of 100 meters on a single breath of air. The body shunts blood and retards some functions to enable this. No other terrestrial animal can match homo sapiens sapiens at diving and endurance swiming, just as no other terrestrial animal is able to match us at overland travel.
And people wondered how it could be that primitive man habitated every corner of the globe before we could read or write.. Pfft.
Man vs Nature.. the road to victory.