Having survived a number of force 9 / 10 storms in the North Sea and English Channel crewing tall ships, as well as nearly being run aground off Portland in a severe storm on the HM Bark Endeavour I appreciate the concept of a 'rolling king.' He would be quite simply a seasoned and accomplished sailor who had his sea legs on a rolling deck and could still work the ropes incl. climbing aloft to hand sail during a severe storm. And in the old days that would be without a harness or any safety lines. Any and indeed all sailors would be expected to be able to work the ropes and keep their footing on the rolling decks of a ship in a storm, &/or climb aloft onto the high yards to bring in or let out sail. If they did do so in those harsh conditions then they would be regarded as 'kings' of their environment by their ship mates. Watch the film of the Peking rounding Cape Horn to see how bad conditions at sea on the old windjammers could be.