Eurogamer has word from Ubisoft on just how open are the open-world aspects of Assassin's Creed 4, as Game director Ashraf Ismail estimates it would take "maybe half an hour" to sail across the whole game world. They say large portions of this will be open ocean, but multiple activities should be visible on the horizon wherever you sail. And for those of us raised on jet travel, they say the fast-travel system has been revamped to allow you to revisit areas without all that should you choose. They accompany the news with this trailer where lead game designer Sebastien Berton introduces the game's take on harpooning, showing concept art and video footage of our character harpooning a Great White Shark from the bow of a small boat (with obvious results). Sebastien's French accent is pretty thick, so closed-captioning may help understand what he's saying.