Setting off from the sports centre its about a mile to the estuary of the river Gannel. There is a crossing up near the hospital round-about that is navigable in all states of the tide though the foot path on the other side might be under water at the highest tides; its probably not a bad idea to check with a local before heading off on a incoming tide. There are several other crossings closer to the Fistral end of Newquay which are tidal but would get you further down the estuary if you're coming from that end.
The path follows the sandy estuary for about a mile until a tributary joins from the left. Cross this and find some rocky steps where the river bears left that lead up onto a grassy field and through a tree lined path, rising gently and still following the river toward the sea.
A little later you drop steeply down to the National Trust car park behind Crantock beach; be prepared in summer to follow families of holiday makers laden with body boards and inflatables but don't worry, once you cross the car park and head back up hill you'll likely be alone again. Crantock is a massive, perfect stretch of sand, popular with holiday makers and surfers alike. According to numerous signs on the beach though the currents are dangerous so you have been warned - stay between the flags people.
At the top of the hill the path crosses sand dunes at the back of the beach before turning right and heading out towards West Pentire, sandwiched between farm land on the left and cliffs to the right. Its up and down for a bit with several options to descend to the beach before the ground eventually opens up onto the headland. From here its a short while before you drop down into the next bay - Polly Joke. This beach is narrow but, at low tide anyway, deep. Its very sheltered and in summer is a great place for a swim.