Carl is at the center of the novel, as he's the reason Kabuo Miyamoto is on trial. Prior to his death, he was a well-liked fisherman who, like many of the other male characters, had fought in World War II and came back from that war changed. Although he and Kabuo had been friends as boys, the war had distanced them and altered Carl's feelings toward the Japanese and Japanese Americans.
Carl was a very manly man, by all reports—tall, broad, virile, and strong. He was not terribly verbal or expressive, but he was a kind and loving father and husband. Also, by agreeing to sell Kabuo back his family's land, he gets some points in his column for having righted the wrong his family committed against the Miyamotos.
Unfortunately, that all went down the night Carl died, so he never got a chance to tell anyone about it, and Kabuo ended up on trial for allegedly killing him.