Fort Stevens and submarine gunfire limits

I-25 followed fishing boats through the Columbia River approaches to avoid minefields and surfaced to attack Fort Stevens on June 21, 1942. The fort had heavy coastal artillery, including 12-inch mortars and disappearing guns, but its commander withheld fire because the submarine lay beyond effective range. Blackout concealed the target, while the submarine's motion and low firing position made accurate night shooting difficult. Its 17 shells mostly landed in a baseball diamond or swamp, with damaged telephone cables the only substantial result. An A-29 Hudson found the submarine, which evaded its bombs and submerged undamaged. The raid nevertheless prompted coastal barbed-wire defenses that entangled the nearby Peter Iredale wreck until the war ended.