diff --git a/tools/editor/wowee_terrain.cpp b/tools/editor/wowee_terrain.cpp
index 5be59fbd..67727f31 100644
--- a/tools/editor/wowee_terrain.cpp
+++ b/tools/editor/wowee_terrain.cpp
@@ -170,6 +170,18 @@ bool WoweeTerrain::exportHeightmapPreview(const pipeline::ADTTerrain& terrain,
     return true;
 }
 
+bool WoweeTerrain::exportWaterMask(const pipeline::ADTTerrain& terrain,
+                                    const std::string& path) {
+    constexpr int res = 16; // One pixel per chunk
+    std::vector<uint8_t> pixels(res * res);
+    for (int ci = 0; ci < 256; ci++)
+        pixels[ci] = terrain.waterData[ci].hasWater() ? 255 : 0;
+
+    std::filesystem::create_directories(std::filesystem::path(path).parent_path());
+    stbi_write_png(path.c_str(), res, res, 1, pixels.data(), res);
+    return true;
+}
+
 int WoweeTerrain::exportAlphaMaps(const pipeline::ADTTerrain& terrain,
                                     const std::string& outputDir) {
     namespace fs = std::filesystem;
diff --git a/tools/editor/wowee_terrain.hpp b/tools/editor/wowee_terrain.hpp
index 695a4bc8..7c88f694 100644
--- a/tools/editor/wowee_terrain.hpp
+++ b/tools/editor/wowee_terrain.hpp
@@ -26,6 +26,10 @@ public:
     static bool exportHeightmapPreview(const pipeline::ADTTerrain& terrain,
                                         const std::string& path);
 
+    // Export water mask as PNG (white=water, black=land)
+    static bool exportWaterMask(const pipeline::ADTTerrain& terrain,
+                                 const std::string& path);
+
     // Import terrain from open format back to ADTTerrain
     static bool importOpen(const std::string& basePath, pipeline::ADTTerrain& terrain);
 };