Lightweight towels a la foutala or similar.
Plastic bags to separate out dry, wet etc.
Beach shoes if not sandy.
Cool bag, not too big, for drinks and any food that can't warm up.
A ball, spade for littles.
A towelling hoodie for each child for after, they normally go home in them.
Shortie wetsuits for all if not really warm.
All of the above fits in an old large shopping bag, and the non food stuff lives in it in the porch when not in use for easy grabbing. We go to the beach a lot! 😂
We have body boards for the kids that live in the back of the van anyway, and depending on where we are going we may take stand up paddle boards. These stay inflated in the garage anyway then just go on the roof. This means taking life jackets too.