Check with your state officials, or better yet, read your appropriate state laws regarding watercraft. In my state, up until a couple years ago, there was no requirement to have the capacity plate anywhere. That changed recently, this paragraph slipped into the code.
20.1-13-19. Display of labels evidencing compliance.The state game and fish department may require the display of seals, labels, plates,insignia, or other devices for the purpose of certifying or evidencing compliance with state or federal safety rules and standards for boats and associated equipment.