21" so far since May. Single hole in the mouth. There are so many factors. Between now and September its all about the same. Late September they'll start Coming out of the deep marshes and staging near back lake and main bays.
We've had several go over 20" this year. Largest so far was back in April at 24". All were gigged by my clients.
This year has been great as far as the quality of flounder being harvested, can't wait until fall!