AceShowbiz - "Titanic" director James Cameron spent his birthday underwater on Monday, August 16 - he dived to the bottom of the world's deepest lake in Russia. The moviemaker turned 56 on Monday and made the day even more special by teaming up with the Fund for Protection of Lake Baikal to embark on a mission below the surface.

Cameron, who is a deep-sea diving pioneer, spent more than three hours exploring underwater and took soil samples from the bottom of the lake as part of the organization's ongoing conservation work. Deputy head of the company Inna Krylova says, "He is delighted. He would really like to continue research."

But Cameron made sure he celebrated his big day in style - by cracking open a bottle of champagne when he resurfaced from the dive.