On Monday, the father and son were seen out with a rod and a small barracuda which they returned to the water.
The 38-year-old and his lad are on the Hawaiian island of Oahu where Chris is filming Jurassic World: Fallen Kingdom.
The actor has taken time off to spend Jack while his wife Anna Faris is in Vancouver, Canada, filming the remake of 1987's Overboard.
Chris donned an orange T-shirt and black shorts as he dangled the fish off the end of his rod, while Jack opted for a red T-shirt for their day out.
On Thursday, it looked as if Jack had taken to the sport like, well, a fish to water, in the two Instagram snaps Chris shared.