Offshore drilling has been strong across the board in 2013, but there are also some important long-term trends emerging that investors need to keep an eye on. 

In 2012, 12 billion barrels of oil equivalent were discovered in more than 5,000 feet of water and in 2013 about half of the world's discovered resources were in excess of 7,500 feet of water. The bottom line is that easy oil has been tapped so more extreme conditions are being tapped for new resources. 

The beneficiaries of this drilling is oil drilling rig owners like Seadrill (SDRL), Transocean (RIG -2.78%), Noble (NEBLQ), and Ensco (VAL), who are charging as much as $600,000 per day for rigs in ultra-deepwater. 

Erin Miller sat down with Fool contributor Travis Hoium to see who he likes in this space.