God of War Ragnarok continues the series tradition of referencing the unfortunate boat captain from the original trilogy, although it's noteworthy here as Kratos finally admits that he was in the wrong.
It probably goes without saying, but Kratos is a very different god in the Norse saga than he was back during his reign in Greece. While he was once a murderer who would kill anyone who was vaguely in his way, he's now an emotional father that tries to hold back from fighting whenever possible. God of War's great characterisation means that it's easy to forget about Kratos' past personality, but one character can bring it all back into frame - the captain.
The captain was a character who appeared in the first God of War, running into Kratos while in a Hydra's mouth. In that game, Kratos killed him twice, once to get the key around his neck, and then a second time in the Underworld to stop himself from falling into the depths. Kratos is awful to many people in the original trilogy, but this over-the-top harshness to one character quickly became a running joke in the series.
After the first game, the captain appeared in God of War 2 as an enemy during a boss fight with the Barbarian King and then made a cameo in the form of a note in the Underworld in God of War 3. 2018's God of War also references the captain, whose boat somehow ends up in the Norse realm and sinks in the Lake of Nine.
As reported by Kotaku, God of War Ragnarok continues this little tradition in a surprising way. In one of the game's early side missions, Kratos and Atreus work together to free a creature in the sea. After completing the side mission, Kratos writes an entry in his journal about it, where he makes reference to the captain, admitting that he "wronged" him and that his actions caused him to be “robbed of his freedom”.