The apparently appalling reliability of the boat is so bad that I find myself asking whether this is a set up by the Navy to garner public sympathy and support for greater investment.
Laid down in 1983, now over 37 years old and filmed in her last cruise prior to decommissioning (which is probably the reason they got permission to film on board.)
I can imagine the RN weren’t prepared to spend much on her except for essential repairs and parts. If a sub has the equivalent of a MEL I’m assuming it had flags and stickers all over it for the last trip….