In Blockade of Germany there is a task to sink 5 AMc. What is it AMC ?
You could try checking out this earlier post with a similar question.
"When you shoot at a destroyer and miss, it's like hit'in a wildcat in the *** with a banjo" by Chief Officer Steward Dogan - USS Gurnard.
SHIV Guide - TMOwTw 2.5 - Shipping Route Maps US & Jap - TriggerMaru_Overhaul_2-5 - SH4 Manual
AMC ( Armed Merchant Cruiser) sink them at Scapa flow labeld as warship look like troop transports but grey