Here I go again, blowing up my spot. I felt like everyone should know though. Queen's Island Preserve is the best secret spot to hit up for Paddleboarding or kayaking.
From the parking lot, just south of Vero Beach on a1a, put in at the canoe launch. The paddle begins in a large sized canal which if you paddle all the way north, eventually hits the larger portion of the Indian River Lagoon.
However, the best paddling to be had is within the maze of smaller, skinny water channels on your left when you head north. Don't worry about getting lost in here, no matter where you are, your pretty much within shouting distance of apartment buildings and homes, even if you can't see them. But you'll definitely know it when you've hit the main backwater channel.
If you live in the area or are visiting the Treasure Coast, this is a must for those seeking the true Florida experience while paddling.