The ferry and cruise port at Harwich isn’t the most accessible place to get to from London, at least compared to the other main cruise and ferry ports at Dover and Southampton. The only realistic public transport option is the hourly rail link from London’s Liverpool Street. Liverpool Street Station itself is tedious to get to from London’s Heathrow and Gatwick airports and for most people with a hotel In London Liverpool Street is the “wrong” side of London making it a time consuming business getting to Harwich.
So staying overnight, prior to to a cruise or ferry makes a lot of sense and Harwich is a very agreeable town to spend a day.
There is not exactly a gret choice of hotels in and around Harwich and the ferry/cruise port is a couple of miles from the Old Town of Harwich. But three hotels that are very suitable are covered below on a video presntation of each hotels vicinity and location. So choose between a great value chain hotel of a good standard close to the cruise and ferry terminal, a historic small hotel in the old port and another small independent hotel in the beach resort of Harwich, Dovercourt.
More details about each hotel is on the main web page for Harwich Hotels.