"Fallout 4" is said to be full of bugs but it is also full of amazing secrets just like the one recently spotted by Modder xxdeathknight72xx.
"Fallout 4" next week will have it first update to fix bugs and improve game experience. Hopefully the update would only wipe out the bugs and not the secrets that not everybody has found yet. According to Kotaku, Modder xxdeathknight72xx has discovered a harpoon gun complete with a bubble-spewing reload animation while going through some RPG files that most players ignored. Based on the lost weapon's firing animation, it suggests that it had been designed for underwater combat.
According to Gamespot, judging by the animation a certain Tryannicon supposes that the weapon could be part of the "Fallout DLC that was coming in 2016" and was not supposed to be found to soon. You can check the harpoon's animation in Tryannicon's YouTube Video. The lost weapon's video quality is not high which magnifies the assumption that it was not meant to be found yet.
Moreover, the harpoon found is said to switch the Railway Gun if you have it in your collection. According to Kotaku, if you play "Fallout 4" on PC you can try using the harpoon gun yourself by using xxdeathknight72xx's mod that you can obtain from Nexus Mods. The modder's descriptions says, "A harpoon gun that seems to have been in the game during beta testing at Beth. This weapon will override the 'Railway Rifle so it works as a harpoon should. It works as it should . . . or at least as far as they coded it to. The reload animation works and there is a trail of bubbles coming off of the harpoon.
And just like the main game, "Fallout 4" xxdeathknight72xx's mod also has its own share of bugs. xdeathknight72xx's wrote, "Ammo is not able to be picked up so you will need to add ammo by opening the command (press ~) and enter player.additem 000fe269 50."