On Thursdays, Fridays or Saturdays travel by Hythe Ferry. Walk up the High Street opposite Town Quay and you'll recognise the Bargate from the picture here.
Otherwise, and on other days, try using the Star 9 bus, which runs from outside our front door to West Quay, just a two minute walk from the Bargate. There are buses back at 9:30 and 11:10 every day, even Sunday - and on weekdays there's one at 10:30 too.