Huge Navy submarine spotted in Firth of Clyde / First of its kind Dutch Navy submarine spotted in Firth of Clyde / Horror moment Egypt Sindbad submarine passenger realised they were suddenly sinking / Terrifying final moments of Egypt submarine passengers revealed by distraught survivors / 'I travelled on Sindbad submarine days before it sank killing 5 - here's what it's like' / 6 dead after tourist submarine sinks off Egypt's coast: officials / Missing Dutch submarine found after 80 years off Australian coast / Royal Navy submarine service rife with 'gang bangs' and 'rape lists' whistleblower reveals / UK's last Trafalgar submarine makes final voyage / British engineers successfully test new uncrewed submarine