minecraft-assets/data/minecraft/worldgen/structure_set/shipwrecks.json

{
  "placement": {
    "type": "minecraft:random_spread",
    "salt": 165745295,
    "separation": 4,
    "spacing": 24
  },
  "structures": [
    {
      "structure": "minecraft:shipwreck",
      "weight": 1
    },
    {
      "structure": "minecraft:shipwreck_beached",
      "weight": 1
    }
  ]
}