A young Wren's result changes fleet instruction

WATU had been established under Percy Noble before Max Horton took over Western Approaches Command in November 1942. During a visit, the experienced submariner chose to play the U-boat commander while Roberts placed the roughly twenty-year-old Janet O'Call in escort command. She outsmarted Horton five times out of five, a result that initially angered but did not close the senior officer's mind. Horton ordered her method examined, incorporated it into revised fleet orders, and required every escort-group commander and deputy passing through Western Approaches to attend WATU. His threat to replace weak commanders with WATU-trained personnel may have been difficult to implement at sea, but it demonstrates how seriously he treated evidence that challenged rank, age, and gender assumptions.