HMS Onyx was an Oberon class submarine of the Royal Navy.
HMS Onyx (S21)
HMS Onyx and other ships at Birkenhead in 2005
The Oberon class was a ship class of 27 British-designed submarines operated by five nations. They were designed as a follow-on from the Porpoise class; physical dimensions were the same but stronger materials were used in hull construction and improved equipment was fitted.
HMS Otus moored at a dock in 2002.
The fin and equipment masts of HMAS Onslow
Barr and Stroud Attack Periscope Type CH74 – RAN Oberon class submarine
Torpedo fire control consoles aboard HMCS Onondaga