I don't know all the details, but in the past, it's been open to anyone. Fill out a registration and pay the entry fee. They typically do it in phases, not just a single day tournament thing. And, it's not based on single biggest fish -- based on largest of specific species, like largest yellowtail, largest snapper, etc. Also, if I'm not mistaken, I think grouper and black seabass are excluded from the derby. Just what I recall about it off the top of my head.