I've never taken my dog to the beach, but I suspect she would like it. There would be things to smell and places to dig holes, and that's really all it takes to make her happy. There are also good places to sleep, but she can really do that anywhere.
The point is that beaches are a perfect place for dogs, so it is no wonder that no one has ever seen an unhappy dog there. Every dog is constantly either playing or sleeping, and only sleeping long enough for them to be reenergized for the next round of playing.
So take your dogs to the beach this summer. They'll thank you later.