Its about a mile away from the Mayflower and City terminals. The QEII terminal is about 1.5 miles. There are no shuttle buses but usually taxis available. You can get maps on this link depending which terminal you are sailing from
All cruise terminals are a short taxi ride from Central Station. You can see the ships from there! They are actually within walking distance, minus suitcases! Happy cruising.
It is a simple 10 min walk - head for the Novotel and then straight through the port gates.