Cruel Seas takes players onto the smaller support ships that were just as vital to the cause of the war. Many times, those ships were escorting and targeting larger vessels, such as this Merchant Tanker that you can pick up now from Warlord Games.
From the website:
Crucial for naval trade, these mammoth sized ships were often preyed upon by enemy vessels.
Tasked with the ferry of supplies such as food, fuel, steel, clothing to munitions and weaponry. Many nations were heavily reliant on such ships completing the journey and securing their goods. As a result, this made them obvious targets for the nimble torpedo boats.