That's right. Surprised me on my first BNY.
Load up in Brooklyn.
There is one water station just before the ferry, but that's all.

Last year at the ferry line there was a group with pizzas. I guess they ordered ahead, them picked them up along the way and ate them while waiting in line.

btw - it they follow the route of most previous years, there is a "fake" rest stop on the pull-over on the Belt Parkway, just before the Verrazano. Several vendors set up there and sell drinks and food. (suppose it might be better than the festival food) If you continue another half mile you get to the real rest stop at Fort Hamilton/Cannonball Park