What if interwar US fleet submarines carried significant mine capacity in addition to torpedoes?
Short answerThey could seed damaging minefields during early Pacific operations, but only if the weapons avoided the reliability problems of American torpedoes.
NotesAdditional mine capacity could let American fleet boats leave dangerous minefields behind during early withdrawal operations. Those mines could threaten an opponent after the submarines had departed. A follow-up joke imagines the mines using the Mark 6 exploder as well, qualifying the expected benefit with the possibility of unreliable weapons.