Utter drivel. I wanted to like this but it's like Dr. Who on a sub (cheap sets, woke and poor acting). There is only so much suspension of belief one can accommodate. Subs are cramped: not this one. Navy crew seen not to be aware of things like discipline, proper uniforms, roles that are realistic (commander manning the guard post!). There is so much 'just so' rubbish that I got so frustrated I stopped half way through episode four.