"What the heck is that?"Researchers controlling the remotely operated underwater vehicle (ROV) Hercules sounded visibly excited when they saw an "extremely rare" sperm whale recently. The encounter occurred nearly 2,000 feet below the Gulf of Mexico near the Louisiana coast.The massive sperm whale brushed up against the Hercules several times, which was caught on tape from cameras equipped on the ROV. Crew members on the Nautilus ship, which is floating at surface level, were aghast and amazed at the sighting as chorus of "wows" are heard. "He's just doing laps!" one exclaimed. "He's trying to figure us out," another said.The chance encounter happened just five days after the Nautilus set sail on a six month mission that will eventually end in British Columbia. The entire mission is being streamed live, so who knows what we'll see next.