If your kids caught Derby fever, make sure you mark your calendar for this Sunday, Sept. 16. Starting at 6 am, the annual Martha’s Vineyard Derby Kids Day runs until 8 am. Unlike the main derby, fish are measured by length, not weight, and buttons and registration are not required. This event is all about fun, friendly fishing, and prizes will be awarded. If your child is age 4 through 14, head to the Oak Bluffs Ferry Wharf at first light this Sunday. For more information, visit mvderby.com.