We'll be in London, staying in Mayfair, and need to get to Harwich to board a cruise ship on a Monday in August. Any advice about the easiest and cheapest way to do that? We can buy a round-trip bus from Heathrow to the boat. But that means getting back to Healthrow.
The Piccadilly tube line will take you to Heathrow. The journey takes about 1hr. The Green Park tube station is right on the southern edge of the Mayfair district. Not too many tube stops in the Mayfair district so you may have to hike over to Green Park. Or, you can go a bit north to the Bond Street tube station and take the Jubilee tube line one stop to Green Park.
For the Liverpool train station that Steve describes, go north to either the Bond Street or the Oxford Circus tube stations and go east to the Liverpool tube station. You can also do this from Green Park but you would transfer to the central tube line at Holborn (3rde stop). It's not really as complicated as it may sound.
A taxi to the Liverpool train station would be a resonable alternative. It's not too far.
Thanks much. Exactly the kind of information I needed.