I always travel "ahead slow" on diesel (on electric power only if I'm close to the target ir I might become a prey) . So diesel most of the time and slow... unless I spot a target in range and at that moment will be flank speed.
The fuel is enough to patrol the grid, go to other zones better for fishing and return to the port in the same way "ahead slow" (teleporting is not an option)...
I reckon that my commander most of the times give us excellent medals. Because we save tons of diesel for the war effort
