User blog comment:Master Sima Yi/Assassinews 28-02-'13 — Assassin's Creed IV: Black Flag revealed/@comment-5638823-20130301131026/@comment-6547588-20130301170251

I may be mistaken but wouldn't free running on a ship at sea be somewhat similar to a tree, not being on a steady surface, looking for hand-holds on the wood of the mast and all that?