Walking
There are some great walks in either direction straight from the flats. The rugged coastline to the north end of the bay around Godrevy lighthouse is worth a visit. This is a National Trust park so if you are a member and have your card you can park for free. One feature of the park is Mutton Cove where from the clifftop one can often see hundreds of seals on the sheltered beach below. If enroute to Portreath you will come across 'Hells Mouth' a very high and steep cliff cavern which is directly exposed to the Atlantic. As waves crash against the base of the cliffs at high tide the noise echoes up the chasm. The cafe at the car park at the top makes a great breakfast.
In the other direction, at very low tide it is possible to walk across the estuary and round to Carbis Bay and St Ives. If the tide is in then one has to walk inland around the estuary and then follow the coastal path. There are some nice pubs on the way for refreshments and food.