The PLA owns Denton Wharf and Jetty in Gravesend, which is the main base for its fleet of more than 40 vessels. It also provides lift-out and maintenance services for other users of the Thames. The PLA owns Barrier Gardens Pier and Unity House, near the Thames Barrier, providing a convenient base for its Driftwood vessels. There are also two pilot stations at Harwich and Ramsgate, beyond the estuary and the Port of London. From these stations pilots are sent out and return from large vessels entering and leaving the Port.