A Whale Warning system is used to alert boaters of whales nearby. The idea is to prevent whale-boat collisions. Whale Warnings are dispersed via apps (Whale Alert), raising a flag on your boat when a whale is sighted, or high tech buoy systems that rely on hydrophones and user reports to issue real-time alerts. Whale strikes can lead to death to both the boaters and the whales, so it's important to pay heed.