Zhang Tie broke his limit in seawater once again.
Zhang Tie's driving force in seawater was provided by the reaction caused by the vacuum effect when seawater was sucked into Castle of Black Iron. Therefore, he adjusted it by his spiritual energy.
A few years ago, when Zhang Tie arrived at Ewentra Archipelago by sea for the first time, he penetrated through 10,000 miles in the water in 3 days with the help of Castle of Black Iron and ocean currents. At that time, Zhang Tie's speed was restricted by his bearing capacity about the friction caused by the water flow. Due to the existence of water friction and stress, Zhang Tie could even gain iron-body fruits on the way.
