Hi, depending on the learning you'd like the activity to impart you could maybe look at sun safety, putting holiday litter in bins, making sandcastles
& adding flags or plan a lighthouse craft and ask why they can be found at the coast, how to pick up crabs if they have to, what's in a water pool, why is seaweed slippery
There's an
activity planner on this thread if you'd like to adapt it xx
Beach themed forum
Ocean themed forum
Summer themed forum
Best wishes with your assessment xx