{
  "feature": "minecraft:seagrass_simple",
  "placement": [
    {
      "type": "minecraft:carving_mask",
      "step": "liquid"
    },
    {
      "type": "minecraft:rarity_filter",
      "chance": 10
    },
    {
      "type": "minecraft:block_predicate_filter",
      "predicate": {
        "type": "minecraft:all_of",
        "predicates": [
          {
            "type": "minecraft:matching_blocks",
            "blocks": "minecraft:stone",
            "offset": [
              0,
              -1,
              0
            ]
          },
          {
            "type": "minecraft:matching_blocks",
            "blocks": "minecraft:water"
          },
          {
            "type": "minecraft:matching_blocks",
            "blocks": "minecraft:water",
            "offset": [
              0,
              1,
              0
            ]
          }
        ]
      }
    },
    {
      "type": "minecraft:biome"
    }
  ]
}