In Kantai Collection, referring to the practice of sending submarine fleet to map 2-3 (Orel Sea) that was very rewarding and low risk for the subs.
Played as a comedy where the submarines (with I-58 as the most common victim) are being worked to death repeating the same mission over and over again (thus, 2-3 all day every day)
After KanColle's Phase 2 update, the Orel cruise is considered obsolete due to the map adjustment.
