I admit the game is funny sometimes in how targets appear...or don't appear.
I had to quit RSRD personally because in 5 patrols I only sank like one ship.
I admire and realize what the author was aiming for and its an amazing undertaking, but personally it just wasn't fun for me. I think the clincher was when I cruised into Tokyo bay and found it completely empty. Kinda spoiled the illusion.
Currently I'm running plain TMo currently and the situation is better.
I still have only two merchant kills in 6 patrols, but there are plenty of destroyers and other oddities to keep me occupied.
I even ran across a fishing boat armed with a 20mm that started taking shots at me. (idiot)
Im not sure how to credit an armed fishing boat. An Auxiliary cruiser? A Q-Sampan? lol
