Fort Stevens and range discipline

I-25 followed fishing boats through the coastal minefields and carried a Yokosuka E14Y reconnaissance seaplane as it approached Fort Stevens. The Civil War-era fort had Endicott-period defenses that included 12-inch mortars and 10-inch and 6-inch disappearing guns. Its commander ordered a blackout and refused to return fire because doing so would reveal the batteries and because the submarine was probably beyond their range. I-25 fired 17 shells, most of which landed in a swamp or baseball field, while the only substantial damage was to telephone cables. An A-29 Hudson located the submarine after the raid, but I-25 evaded the falling bombs and submerged. Range discipline and concealment limited the raid to minor damage and psychological effect.