James Cameron is king of the deep blue sea. Using a specially designed one-man submarine dubbed the "Deepsea Challenger," the 'Titanic' and 'Avatar' director reached the floor of the Pacific Ocean's Mariana Trench, the deepest part of the world's oceans. He is now the first solo explorer to ever do so.

So what did Cameron do when he hit bottom early Monday morning? Well, he tweeted. Cameron told his followers in a message relayed through the expedition's mother ship:

In January of 1960, Navy lieutenants Don Walsh and Jacques Piccard became the first humans to reach the trench's floor of 35,756 feet below sea level (nearly seven miles). Prior to Cameron, no one had attempted a similar dive.

The Deapsea Challenger was rigged with multiple 3D cameras, so we should expect Cameron's underwater adventure to eventually hit movie theaters. For now, you can check out a video of Cameron returning to the surface below. Truly he can now claim to be "king of the world" and the sea.