Where Britain could place two long-lived naval dry docks

Where should Britain build two new large naval dry docks?

Portsmouth and the Cammell Laird area on the Mersey offer a useful combination of naval access, existing industry, and long-term resilience.

Portsmouth offers direct naval access, while the Cammell Laird area on the Mersey offers industrial resilience. Infrastructure expected to serve for fifty or sixty years must be placed with long-term strategic conditions in mind, and a double-ended Mersey dock built partly into the river could serve that purpose.