just as an experiment... try it with no weapons officer assistance and see if your tonnage influx changes per mission. :hmm:
on 100% realism... if i encounter a convoy of large tankers i would have to shadow them for a week to rack up 72K tons. plotting your own solutions is a bit more difficult than the weapons officer finishing his magical 100% accurate solution in 2 seconds. and it takes a few minutes when you plot your own plus you have your margin of error built in.
On a good night im lucky if i take down 3 ships before i have to start thinking about evading escorts.
just out of curiosity... what was the information source for the tonnoge of the average merchant ship? i would like to research that