In reality, Ling Han wasn't delaying their journey because he was afraid of Jiang Anyun.
A ship would depart from Tyrant Axe Harbor every three days, yet the sizes of these ships varied.
For example, the ship this time was a large-sized ship that could hold more passengers. Moreover, it had the highest safety rating out of all the ships as it had a powerful elite at the Sun Moon Tier guarding it.
However, Ling Han and Shui Yanyu had come to exterminate pirates, so the more powerful were the people on their ship, the less likely they were to be targeted by pirates. Thus, they naturally wouldn't choose to take such a ship.
They had to wait for a small ship that was only guarded by a cultivator at the consummate level of the Mountain River Tier as this would greatly increase their chances of being targeted by pirates.