How do I know which model sub Im in?

[Bathrone]

Sorry for a basic Q but how do I actually know what model sub Im in?

Obviously my upgrade from the type 7A was clear, but for those minor increments in design where do I actually see what Im in?

Thanks

[V13dweller]

The 7A has a rear torpedo tube on the above water line and a Net Cutter on the front.

7B has a Net Cutter on the front, but no rear tube above the waterline.

7C has no Net Cutter or above water torpedo tube.

7C/41 has a built in radar and a radar housing built into the conning tower, no net cutter or above water torpedo tube.