This is the world’s first glass reinforced plastic submarine built by Vickers .
The LR2 was 7m long, had a 3m beam, 2.5m in height and could dive to 400m. This was taken in around 1977 when Shell was using it on Brent. Its sister ship, the LR3 worked for BP on Ninian.
I think this was built in the Slingsby factory in Yorkshire where Forum build their Triton ROVs. Anyone that has been there could attest that you couldn’t get much further from the sea.
The PC 1802 submersible permanently installed in the Northern Installer. It had a maximum diving depth of 300m. The four-man submersible was supplied and operated by Intersub. It had a lock out capability for two divers.