333 U-Boat Original Pictures

Collection S. Mata

Ship’s Gross Registred Tonnage (GRT) sunk by U-Boats (each month).

Accumulated number of lost U-Boats from the beginning of the war.

Balanced number of enlisted U-Boats (at the beginning of each month).

Data from Rohwer (and Tarrant, when these are smaller).

EFFICIENCY and RENTABILITY of the U-Boats

EFFICIENCY: GRT sunk by each enlisted U-Boat (absolute number on each month).

RENTABILITY: GRT sunk by each lost U-Boat (accumulated).

Accumulated number of lost U-Boats from the beginning of the war.

Balanced number of enlisted U-Boats (at the beginning of each month).