After returning to shore, Zhang Heng did some tests on his new abilities. The test included how long he could breathe underwater, his ability to move underwater, his limitation, the limits of manipulating water flow, and so on.
Still, Zhang Heng could not find a clear answer to those questions. After taking off his breathing equipment in that underwater palace, he stayed there for at least seven to eight hours, and he did not feel any discomfort.
Upon returning, Zhang Heng found a swimming pool and tried to stay in it for 24 hours. He found out that his newfound ability did not only apply to the sea. He could also breathe unrestrictedly under the dead water in the swimming pool. Therefore, Zhang Heng now knew that there were no restrictions to his underwater breathing ability.
