vanjast has the thr right ideas.Also if you like to run surface attacks better to have TMO or RFB. I can pull off outstanding surface attacks in TMO1.7 other day I was in an S-boat out of Cavite in '41 and ran into a landingship task force. Since i was in the slow old S-boat I knew by the heading of the task force I could only hope to hit the troop ships(the most vital target in this type of task force anyway.) So I ran at Flank speed a whopping 13knts in my sweet old sugar boat.
I posted my sub so that I could come in and get hopefully 2 of the troop ships with the mk.10s but I just could not not get into range even at full speed so I had only one option the 4inch as I was only 6000 yds from the nearst troop ship(a very dark night)I felt this was pretty ballsy as there where 2 DD only about 8000yds away but for some reason all the DDs had stayed at the head of the task force leaving the flanks naked so I was able to sink one troop ship and badly damage a second before I had to turn away and dive to get away from the DDs. Surface attacks can be done but aginst ships with radar you can forget about it.The speed used in relation to the light condtions and coming in as much as head on as you can are most vital.Also I mostly use torpedos with surface attacks not the deck gun. A good torpedo attack on the surface at night can so confuse the bad guys they sometimes may start dropping charges thinking that you are under water!