Wild swimming (yes, we used to call it just 'swimming) is the cheapest thing you can do, and the beaches at South & North Sands and Splat Cove (if you can find it) are excellent and fairly safe places to do it. Kayaking and paddle-great fun too. If you prefer to remain dry, or just don't have the energy to walk in to Salcombe, then let the Salcombe Ferry take the strain. For Mill Bay beach and longer walks around the headland towards Gara Rock and Prawle Point by taking the ferry from Salcombe to East Portlemouth. Hiring boats is expensive, but day charters and fishing can be booked. It's all about the water...