Tracking whales in the wild is not that easy in the deep, dark waters of our Indian Ocean. But it is this unpredictability of wild encounters that makes whale watching so exciting; that constant scanning of the horizon in anticipation for the tell-tale signs of whale activity. The most obvious signs to look out for are their exhalations as they surface to breathe. This spray, known simply as ‘the blow’, is often visible from far away. On cold winter days it is even more noticeable, as their breath is released into the comparably lower-pressure, colder atmosphere and any water vapour then condenses. Whales surface intermittently to breath, and when they submerge once again beneath the water, one has to look for certain signs to try and predict where they may resurface again. The most telling sign is what is known as a whale’s ‘footprint’.
Because it is often not possible to see the whales beneath the surface, this ‘footprint’ allows one to track them without actually seeing them. The footprint is a glassy, smooth circle and is a consequence of the whale’s forward motion. The extremely powerful motion of their flukes creates a vortex, which is clearly visible on the surface as it is clear and smooth compared the rest of the ocean’s restless surface. These footprints make tracking the whales a little bit easier for both researchers and whale watchers.
Interestingly, the slick waters of their footprints were once thought to have been created by a whale’s oil seeping out of its body and floating on the surface.