My wife found this on the beach.
Alt Text: A plastic card with a form on it. Holes on the left for putting into a notebook. It’s for noting submarine locations. It has a few confusing illustrations and a bunch of text: Ranged - Surface Range- سياة LECHOES STANAS! STEADY Layer Depth Periscope-Depth Range Layer Depth Range Pattern MEDIUM Any Depth PETER WIND FORCE 6-7 FILL IN BLANKS WITH PENCIL: Periscope-Depth Range-MEDIUM Layer Depth Range at Depth • Range Pattern. Assured Range= Range at Depth os 1300 yards, whichever is shorter. 15 1000-2000 yards feet yards PETER NO ECHOES Kange at Of Deptho - RANGE LINE Search keying interval for loose screen. • Search keying interval Assured Range of 1200-1300 yards. for tight screen for Assured Range less than 1200 yards. • Most effective search speed.... • Spacing in scouting line 3/2 times Assured Range = Maximum spacing in tight screen • If range of first contact exceeds. shen conning tower of submarine is above • 2 times Range at Depth =_ ..Layer Depth = • During reattack, contact may be lost if range is opened beyond Assured Range. If Surface Range is more than 2500 yards, use card 4 or 7. If Surface Range is less than 1300 yards, use card 17. TYPICAL BATHYTHERMOGRAPH TRACE 2000 2000 1000 15-18 yards yards yards yards knots yards yards feet. CONFIDENTIAL