What are you do for a living? Just ducking and diving! That’s what the Canal & Rivers Trust gets brave surveyors doing, delving into mud and the depths of the old Millwall Docks in London’s East End.

The divers are looking for nooks and crannies in the ageing 19th century dock gates and old dock walls of the West India Dock.

“We’re getting a detailed picture of all the underwater infrastructure,” the Trust’s Charles Baker explained.

“This will tell us what works we need to do to maintain the docks—diving is the last piece of the jigsaw.”

The survey of West India Dock is to make sure the lock gates are up to scratch, each weighing 160 tonnes. The lock is the only entrance for boats from the Thames.

The divers search for any voids or gaps that may have opened that need plugging.

The Canal Trust, which looks after 2,000 miles of the former British Waterways network, has been working with the Port of London Authority over the past 12 months to survey four miles of dock walls that the charity looks after, with this final diving inspection completing the project.

Construction of the docks on the Isle of Dogs goes back as far as the Napoleonic Wars, which were then expanded later in the 19th century as London became the hub for world trade.

The London docks continued to boom up to the 1960s, handling as much as 61 million tonnes of goods in 1964 alone.

But changes to shipping methods such as containers led to a decline and general cargo operations which eventually stopped in the 1980s, before the Docklands area around Canary Wharf and the Millwall Docks was reclaimed for business, housing and entertainment.