Trains leave London's Paddington Station for Truro several times a day. The trip takes 4 1/2 to 5 hours. For schedules and information, call tel. 0845/748-4950 or visit www.nationalrail.co.uk. Passengers transfer at Truro to one of the two buses that make the 45-minute bus trip from Truro to St. Mawes. It's much easier to take a taxi from either Truro or, even better, from the village of St. Austell, which is the train stop before Truro.
Buses leave London's Victoria Coach Station three times a day for Truro. The bus takes 7 1/2 hours. For schedules and information, call tel. 0871/781-81-81 or visit www.nationalexpress.com.
If you're driving to St. Mawes, turn left off the A390 (the main road along the southern coast of Cornwall) at a junction 6.5km (4 miles) past St. Austell, onto the Tregony road, which will take you into St. Mawes.
A ferry travels to St. Mawes from both Falmouth and Truro, but schedules are erratic, varying with the tides and the weather conditions.