Commando Comic #5170 'Sea of Secrets' (2018)
 
When Tim Elder, young and keen, his sub lieutenant’s rank badge shining new, received a posting to the Mediterranean, he found that he had joined a part of the Royal Navy that he knew nothing about.
 
For instance, what was the secret of the grubby fishing vessel that made the Germans determined to sink her? And where were the secret passages through the danger‑ridden reefs that could mean the difference between life or death?
 
If Tim were to survive, he had to learn these secrets – and learn them fast!