Hello. In my game, the Yangtze-31 submarine vanished not long after the quest "Here There Be Monsters" (editor ID: MS02). Based on my research, it is not physically supposed to: https://www.reddit.com/r/fo4/comments/a4anwi/does_the_yangtze_actually_leave/ https://fallout.fandom.com/wiki/Here_There_Be_Monsters I have been told that this is done by the Unofficial Fallout 4 Patch ( UFO4P, https://www.nexusmods.com/fallout4/mods/4598 ). It is disabling the sub's exterior and map marker to simulate the sub leaving the Commonwealth. If this is accurate, then I understand that it is for immersion. However, it does pose a problem for those who have installed mods, post quest, that make use of that interior cell. Examples: Stealth Suit: https://www.nexusmods.com/fallout4/mods/20959 Red Menace: https://www.nexusmods.com/fallout4/mods/47755 Respectfully, I request a mod or patch that can either A) undo what the UFO4P does and restores the Yangtze-31 exterior and map marker to their original positions. or B) Better still, moves the Yangtze's exterior and map marker further out into the harbor, pointing it out to sea... this could simulate the sub leaving without hampering mods that make use of that cell. Note: To anyone having this issue. Until a mod/patch is created, it is possible to get back to the Yangtze by teleporting to Captain Zao, "player.moveto 0003401C". If he is dead in your game, he will have to be revived, "resurrect 0003401C". Other Site Reference: https://www.reddit.com/r/Fallout/comments/kvai4h/fallout_4_yangtze_disappeared_bug/ Thank you for your time.