"represent approximately 60%" but when counting the 'global experience' land and sea is "about 50-50."
Unlike in Assassin's Creed III, in Black Flag the sea is an open world environment with dynamic events. It's powered by the Horizon System which feed us 'systematically evolved' opportunities.
Landlubber fans of the series needn't worry because "free-running, social stealth and combat are still the key pillars" of AC4 gameplay, with naval action spicing it up.
Creative director Jean Guesdon said that, "mission wise, land missions will represent approximately 60% of the game and naval ones 40%. But if you take the global experience that players will leave with we're more talking about 50-50." Land-based gameplay "remains important" but is no longer the sole focus. Free-running is possible when boarding ships.
"The Seamless, systemic open-world system (Horizon System) packed full of sea and underwater activities will represent a big part of the game," continued Guesdon.
"At any given moment in the game when you are aboard your ship you can take out your spyglass and survey the world. The Horizon system ensures that you will always have 2 or 3 pirate 'opportunities' available to you. That could be a merchant ship convoy to rob, a whale to hunt, fellow pirates to rescue... the list goes on."
"These opportunities happen systemically and evolve based on your progress, meaning that every player's experience will be different. It means that if you love the naval experience you can play it as much as you want, being constantly and variably challenged outside the main story path."
Assassin's Creed 4: Black Flag releases on Xbox 360, PS3 and PC October 29th, and later on PS4.