On Eternal Patrol: U.S.S. Grunion

FRI 31 JUL 1942
Pacific

Submarine Grunion (SS-216) torpedoes Japanese transport Kashima Maru off Kiska, Aleutians, but is sunk by gunfire from her quarry, 10 miles north of Segula Island.

[The Wiki/rest of the story. Different Japanese ship? Torpedo trouble?]

PBYs attempt to bomb Japanese bases in Tulagi-Gavutu area is aborted because of bad weather.

Atlantic
German submarine U-751 lays mines off Charleston, South Carolina.