Portcities is a useful site if you are interested in the role of ports in British history. It is a partnership of port heritage websites, providing a web gateway to their collections, and will grow as more museums, libraries and archives join up.
It currently has material on London, Bristol, Hartlepool, Liverpool and Southampton.
In the London section is an interesting section on Henry VIII's royal dockyards at Deptford and Woolwich . These docks and shipyards played an important role in the early development of the Royal Navy, and Elizabeth I further developed the facilities at Woolwich.
Later on, the reputation of the shipyards encouraged a visit in 1698 by Peter the Great of Russia. Apparently his drunken parties messed up the home of diarist John Evelyn, whose house he was staying at.
Both yards went into decline after the Napoleonic Wars ended in 1815, as new facilities were built closer to Europe (e.g. at Chatham), more suited to building larger ships. Both Deptford and Woolwich closed in 1869, having played a key role in the Royal Navy's formative years.