diff --git a/src/noggit/ChunkWater.cpp b/src/noggit/ChunkWater.cpp
index 3585bc7a..4d941a2b 100755
--- a/src/noggit/ChunkWater.cpp
+++ b/src/noggit/ChunkWater.cpp
@@ -120,7 +120,7 @@ void ChunkWater::fromFile(BlizzardArchive::ClientFile &f, size_t basePos)
 }
 
 
-void ChunkWater::save(sExtendableArray& adt, int base_pos, int& header_pos, int& current_pos)
+void ChunkWater::save(util::sExtendableArray& adt, int base_pos, int& header_pos, int& current_pos)
 {
   MH2O_Header header;
 
@@ -159,7 +159,7 @@ void ChunkWater::save(sExtendableArray& adt, int base_pos, int& header_pos, int&
     }
   }
 
-  memcpy(adt.GetPointer<char>(header_pos), &header, sizeof(MH2O_Header));
+  memcpy(adt.GetPointer<char>(header_pos).get(), &header, sizeof(MH2O_Header));
   header_pos += sizeof(MH2O_Header);
 }
 
diff --git a/src/noggit/ChunkWater.hpp b/src/noggit/ChunkWater.hpp
index 8838b79c..d8d413b3 100755
--- a/src/noggit/ChunkWater.hpp
+++ b/src/noggit/ChunkWater.hpp
@@ -4,12 +4,12 @@
 #include <noggit/liquid_layer.hpp>
 #include <noggit/MapHeaders.h>
 #include <noggit/tool_enums.hpp>
+#include <util/sExtendableArray.hpp>
 
 #include <vector>
 #include <set>
 #include <optional>
 
-class sExtendableArray;
 class MapChunk;
 class TileWater;
 
@@ -31,7 +31,7 @@ public:
 
   void from_mclq(std::vector<mclq>& layers);
   void fromFile(BlizzardArchive::ClientFile& f, size_t basePos);
-  void save(sExtendableArray& adt, int base_pos, int& header_pos, int& current_pos);
+  void save(util::sExtendableArray& adt, int base_pos, int& header_pos, int& current_pos);
 
   bool is_visible ( const float& cull_distance
                   , const math::frustum& frustum
diff --git a/src/noggit/MapChunk.cpp b/src/noggit/MapChunk.cpp
index e4e1d2c9..ff5bb7a9 100755
--- a/src/noggit/MapChunk.cpp
+++ b/src/noggit/MapChunk.cpp
@@ -1427,7 +1427,7 @@ void MapChunk::setFlag(bool changeto, uint32_t flag)
   registerChunkUpdate(ChunkUpdateFlags::FLAGS);
 }
 
-void MapChunk::save(sExtendableArray& lADTFile
+void MapChunk::save(util::sExtendableArray& lADTFile
                     , int& lCurrentPosition
                     , int& lMCIN_Position
                     , std::map<std::string, int> &lTextures
@@ -1443,7 +1443,7 @@ void MapChunk::save(sExtendableArray& lADTFile
 
                                                                                                    // MCNK data
   // lADTFile.Insert(lCurrentPosition + 8, 0x80, reinterpret_cast<char*>(&(header)));
-  MapChunkHeader *lMCNK_header = lADTFile.GetPointer<MapChunkHeader>(lCurrentPosition + 8);
+  auto const lMCNK_header = lADTFile.GetPointer<MapChunkHeader>(lCurrentPosition + 8);
 
   header_flags.flags.do_not_fix_alpha_map = 1;
 
@@ -1505,9 +1505,13 @@ void MapChunk::save(sExtendableArray& lADTFile
   lADTFile.Extend(8 + lMCVT_Size);
   SetChunkHeader(lADTFile, lCurrentPosition, 'MCVT', lMCVT_Size);
 
-  lADTFile.GetPointer<MapChunkHeader>(lMCNK_Position + 8)->ofsHeight = lCurrentPosition - lMCNK_Position;
+  // lADTFile.GetPointer<MapChunkHeader>(lMCNK_Position + 8)->ofsHeight = lCurrentPosition - lMCNK_Position;
 
-  float* lHeightmap = lADTFile.GetPointer<float>(lCurrentPosition + 8);
+  auto header_ptr = lADTFile.GetPointer<MapChunkHeader>(lMCNK_Position + 8);
+
+  header_ptr->ofsHeight = lCurrentPosition - lMCNK_Position;
+
+  auto const lHeightmap = lADTFile.GetPointer<float>(lCurrentPosition + 8);
 
   for (int i = 0; i < mapbufsize; ++i)
     lHeightmap[i] = mVertices[i].y - mVertices[0].y;
@@ -1522,15 +1526,15 @@ void MapChunk::save(sExtendableArray& lADTFile
     lMCCV_Size = mapbufsize * sizeof(unsigned int);
     lADTFile.Extend(8 + lMCCV_Size);
     SetChunkHeader(lADTFile, lCurrentPosition, 'MCCV', lMCCV_Size);
-    lADTFile.GetPointer<MapChunkHeader>(lMCNK_Position + 8)->ofsMCCV = lCurrentPosition - lMCNK_Position;
+    header_ptr->ofsMCCV = lCurrentPosition - lMCNK_Position;
 
-    unsigned int *lmccv = lADTFile.GetPointer<unsigned int>(lCurrentPosition + 8);
+    auto const lmccv = lADTFile.GetPointer<unsigned int>(lCurrentPosition + 8);
 
     for (int i = 0; i < mapbufsize; ++i)
     {
-      *lmccv++ = ((unsigned char)(mccv[i].z * 127.0f) & 0xFF)
-        + (((unsigned char)(mccv[i].y * 127.0f) & 0xFF) << 8)
-        + (((unsigned char)(mccv[i].x * 127.0f) & 0xFF) << 16);
+      lmccv[i] = (((unsigned char)(mccv[i].z * 127.0f) & 0xFF) <<  0)
+               + (((unsigned char)(mccv[i].y * 127.0f) & 0xFF) <<  8)
+               + (((unsigned char)(mccv[i].x * 127.0f) & 0xFF) << 16);
     }
 
     lCurrentPosition += 8 + lMCCV_Size;
@@ -1538,7 +1542,7 @@ void MapChunk::save(sExtendableArray& lADTFile
   }
   else
   {
-    lADTFile.GetPointer<MapChunkHeader>(lMCNK_Position + 8)->ofsMCCV = 0;
+    header_ptr->ofsMCCV = 0;
   }
 
   // MCNR
@@ -1547,9 +1551,9 @@ void MapChunk::save(sExtendableArray& lADTFile
   lADTFile.Extend(8 + lMCNR_Size);
   SetChunkHeader(lADTFile, lCurrentPosition, 'MCNR', lMCNR_Size);
 
-  lADTFile.GetPointer<MapChunkHeader>(lMCNK_Position + 8)->ofsNormal = lCurrentPosition - lMCNK_Position;
+  header_ptr->ofsNormal = lCurrentPosition - lMCNK_Position;
 
-  char * lNormals = lADTFile.GetPointer<char>(lCurrentPosition + 8);
+  auto const lNormals = lADTFile.GetPointer<char>(lCurrentPosition + 8);
 
   auto& tile_buffer = mt->getChunkHeightmapBuffer();
   int chunk_start = (px * 16 + py) * mapbufsize * 4;
@@ -1582,8 +1586,8 @@ void MapChunk::save(sExtendableArray& lADTFile
   lADTFile.Extend(static_cast<long>(8 + lMCLY_Size));
   SetChunkHeader(lADTFile, lCurrentPosition, 'MCLY', static_cast<int>(lMCLY_Size));
 
-  lADTFile.GetPointer<MapChunkHeader>(lMCNK_Position + 8)->ofsLayer = lCurrentPosition - lMCNK_Position;
-  lADTFile.GetPointer<MapChunkHeader>(lMCNK_Position + 8)->nLayers = texture_set ? static_cast<std::uint32_t>(texture_set->num()) : 0;
+  header_ptr->ofsLayer = lCurrentPosition - lMCNK_Position;
+  header_ptr->nLayers = texture_set ? static_cast<std::uint32_t>(texture_set->num()) : 0;
 
   std::vector<std::vector<uint8_t>> alphamaps;
 
@@ -1596,7 +1600,7 @@ void MapChunk::save(sExtendableArray& lADTFile
     // MCLY data
     for (size_t j = 0; j < texture_set->num(); ++j)
     {
-      ENTRY_MCLY * lLayer = lADTFile.GetPointer<ENTRY_MCLY>(lCurrentPosition + 8 + 0x10 * static_cast<unsigned long>(j));
+      auto const lLayer = lADTFile.GetPointer<ENTRY_MCLY>(lCurrentPosition + 8 + 0x10 * static_cast<unsigned long>(j));
 
       lLayer->textureID = lTextures.find(texture_set->filename(j))->second;
       lLayer->flags = texture_set->flag(j);
@@ -1659,12 +1663,12 @@ void MapChunk::save(sExtendableArray& lADTFile
   lADTFile.Extend(8 + lMCRF_Size);
   SetChunkHeader(lADTFile, lCurrentPosition, 'MCRF', lMCRF_Size);
 
-  lADTFile.GetPointer<MapChunkHeader>(lMCNK_Position + 8)->ofsRefs = lCurrentPosition - lMCNK_Position;
-  lADTFile.GetPointer<MapChunkHeader>(lMCNK_Position + 8)->nDoodadRefs = static_cast<std::uint32_t>(lDoodadIDs.size());
-  lADTFile.GetPointer<MapChunkHeader>(lMCNK_Position + 8)->nMapObjRefs = static_cast<std::uint32_t>(lObjectIDs.size());
+  header_ptr->ofsRefs = lCurrentPosition - lMCNK_Position;
+  header_ptr->nDoodadRefs = static_cast<std::uint32_t>(lDoodadIDs.size());
+  header_ptr->nMapObjRefs = static_cast<std::uint32_t>(lObjectIDs.size());
 
   // MCRF data
-  int *lReferences = lADTFile.GetPointer<int>(lCurrentPosition + 8);
+  auto const lReferences = lADTFile.GetPointer<int>(lCurrentPosition + 8);
 
   lID = 0;
   for (std::list<int>::iterator it = lDoodadIDs.begin(); it != lDoodadIDs.end(); ++it)
@@ -1692,13 +1696,13 @@ void MapChunk::save(sExtendableArray& lADTFile
     lADTFile.Extend(8 + lMCSH_Size);
     SetChunkHeader(lADTFile, lCurrentPosition, 'MCSH', lMCSH_Size);
 
-    lADTFile.GetPointer<MapChunkHeader>(lMCNK_Position + 8)->ofsShadow = lCurrentPosition - lMCNK_Position;
-    lADTFile.GetPointer<MapChunkHeader>(lMCNK_Position + 8)->sizeShadow = 0x200;
+    header_ptr->ofsShadow = lCurrentPosition - lMCNK_Position;
+    header_ptr->sizeShadow = 0x200;
 
-    char * lLayer = lADTFile.GetPointer<char>(lCurrentPosition + 8);
+    auto const lLayer = lADTFile.GetPointer<char>(lCurrentPosition + 8);
 
     auto shadow_map = compressed_shadow_map();
-    memcpy(lLayer, shadow_map.data(), 0x200);
+    memcpy(lLayer.get(), shadow_map.data(), 0x200);
 
     lCurrentPosition += 8 + lMCSH_Size;
     lMCNK_Size += 8 + lMCSH_Size;
@@ -1706,22 +1710,22 @@ void MapChunk::save(sExtendableArray& lADTFile
   else
   {
     header_flags.flags.has_mcsh = 0;
-    lADTFile.GetPointer<MapChunkHeader>(lMCNK_Position + 8)->ofsShadow = 0;
-    lADTFile.GetPointer<MapChunkHeader>(lMCNK_Position + 8)->sizeShadow = 0;
+    header_ptr->ofsShadow = 0;
+    header_ptr->sizeShadow = 0;
   }
 
   // MCAL
   lADTFile.Extend(8 + lMCAL_Size);
   SetChunkHeader(lADTFile, lCurrentPosition, 'MCAL', lMCAL_Size);
 
-  lADTFile.GetPointer<MapChunkHeader>(lMCNK_Position + 8)->ofsAlpha = lCurrentPosition - lMCNK_Position;
-  lADTFile.GetPointer<MapChunkHeader>(lMCNK_Position + 8)->sizeAlpha = 8 + lMCAL_Size;
+  header_ptr->ofsAlpha = lCurrentPosition - lMCNK_Position;
+  header_ptr->sizeAlpha = 8 + lMCAL_Size;
 
-  char * lAlphaMaps = lADTFile.GetPointer<char>(lCurrentPosition + 8);
+  auto lAlphaMaps = lADTFile.GetPointer<char>(lCurrentPosition + 8);
 
   for (auto& alpha : alphamaps)
   {
-    memcpy(lAlphaMaps, alpha.data(), alpha.size());
+    memcpy(lAlphaMaps.get(), alpha.data(), alpha.size());
     lAlphaMaps += alpha.size();
   }
 
@@ -1737,14 +1741,14 @@ void MapChunk::save(sExtendableArray& lADTFile
   lADTFile.Extend(8 + lMCSE_Size);
   SetChunkHeader(lADTFile, lCurrentPosition, 'MCSE', lMCSE_Size);
 
-  lADTFile.GetPointer<MapChunkHeader>(lMCNK_Position + 8)->ofsSndEmitters = lCurrentPosition - lMCNK_Position;
-  lADTFile.GetPointer<MapChunkHeader>(lMCNK_Position + 8)->nSndEmitters = lMCSE_Size / 0x1C;
+  header_ptr->ofsSndEmitters = lCurrentPosition - lMCNK_Position;
+  header_ptr->nSndEmitters = lMCSE_Size / 0x1C;
 
   lCurrentPosition += 8;
 
   for (auto& sound_emitter : sound_emitters)
   {
-      ENTRY_MCSE* MCSE = lADTFile.GetPointer<ENTRY_MCSE>(lCurrentPosition);
+      auto const MCSE = lADTFile.GetPointer<ENTRY_MCSE>(lCurrentPosition);
 
       MCSE->soundId = sound_emitter.soundId;
 
diff --git a/src/noggit/MapChunk.h b/src/noggit/MapChunk.h
index 9c4f7a99..8eb8c9fc 100755
--- a/src/noggit/MapChunk.h
+++ b/src/noggit/MapChunk.h
@@ -3,16 +3,19 @@
 #pragma once
 #include <noggit/map_enums.hpp>
 #include <noggit/MapTile.h> // MapTile
+#include <noggit/Misc.h>
 #include <noggit/ModelInstance.h>
 #include <noggit/Selection.h>
 #include <noggit/TextureManager.h>
 #include <noggit/WMOInstance.h>
+#include <noggit/map_enums.hpp>
 #include <noggit/texture_set.hpp>
 #include <noggit/tool_enums.hpp>
 #include <noggit/ContextObject.hpp>
 #include <opengl/scoped.hpp>
 #include <opengl/texture.hpp>
-#include <noggit/Misc.h>
+#include <util/sExtendableArray.hpp>
+
 #include <optional>
 #include <map>
 #include <memory>
@@ -31,7 +34,6 @@ namespace math
 }
 class Brush;
 class ChunkWater;
-class sExtendableArray;
 class QPixmap;
 
 using StripType = uint16_t;
@@ -194,7 +196,7 @@ public:
   void clearHeight();
 
   //! \todo this is ugly create a build struct or sth
-  void save(sExtendableArray &lADTFile
+  void save(util::sExtendableArray &lADTFile
             , int &lCurrentPosition
             , int &lMCIN_Position
             , std::map<std::string, int> &lTextures
diff --git a/src/noggit/MapHeaders.h b/src/noggit/MapHeaders.h
index 97077db0..7e58ae17 100755
--- a/src/noggit/MapHeaders.h
+++ b/src/noggit/MapHeaders.h
@@ -122,8 +122,8 @@ struct ENTRY_MODF
 
 struct MapChunkHeader {
   uint32_t flags = 0;
-  uint32_t ix;
-  uint32_t iy;
+  uint32_t ix = 0;
+  uint32_t iy = 0;
   uint32_t nLayers = 0;
   uint32_t nDoodadRefs = 0;
   uint32_t ofsHeight = 0;
@@ -143,9 +143,9 @@ struct MapChunkHeader {
   uint32_t nSndEmitters = 0;
   uint32_t ofsLiquid = 0;
   uint32_t sizeLiquid = 0;
-  float  zpos;
-  float  xpos;
-  float  ypos;
+  float  zpos = 0.0f;
+  float  xpos = 0.0f;
+  float  ypos = 0.0f;
   uint32_t ofsMCCV = 0;
   uint32_t unused1 = 0;
   uint32_t unused2 = 0;
diff --git a/src/noggit/MapTile.cpp b/src/noggit/MapTile.cpp
index aca320a3..16a2eab9 100755
--- a/src/noggit/MapTile.cpp
+++ b/src/noggit/MapTile.cpp
@@ -18,6 +18,7 @@
 #include <opengl/shader.hpp>
 #include <external/tracy/Tracy.hpp>
 #include <util/CurrentFunction.hpp>
+#include <util/sExtendableArray.hpp>
 
 #include <noggit/World.inl>
 #include <QtCore/QSettings>
@@ -275,6 +276,8 @@ void MapTile::finishLoading()
     assert(fourcc == 'MH2O');
 
     Water.readFromFile(theFile, ofsW);
+
+    // Water.update_underground_vertices_depth();
   }
 
   // - MFBO ----------------------------------------------
@@ -633,7 +636,7 @@ void MapTile::saveTile(World* world)
     texture.second = lID++;
 
   // Now write the file.
-  sExtendableArray lADTFile;
+  util::sExtendableArray lADTFile;
 
   int lCurrentPosition = 0;
 
@@ -709,7 +712,7 @@ void MapTile::saveTile(World* world)
 
   // MMID data
   // WMO model names
-  int * lMMID_Data = lADTFile.GetPointer<int>(lCurrentPosition + 8);
+  auto const lMMID_Data = lADTFile.GetPointer<int>(lCurrentPosition + 8);
 
   lID = 0;
   for (auto const& model : lModels)
@@ -744,7 +747,7 @@ void MapTile::saveTile(World* world)
   lADTFile.GetPointer<MHDR>(lMHDR_Position + 8)->mwid = lCurrentPosition - 0x14;
 
   // MWID data
-  int * lMWID_Data = lADTFile.GetPointer<int>(lCurrentPosition + 8);
+  auto const lMWID_Data = lADTFile.GetPointer<int>(lCurrentPosition + 8);
 
   lID = 0;
   for (auto const& object : lObjects)
@@ -759,7 +762,7 @@ void MapTile::saveTile(World* world)
   lADTFile.GetPointer<MHDR>(lMHDR_Position + 8)->mddf = lCurrentPosition - 0x14;
 
   // MDDF data
-  ENTRY_MDDF* lMDDF_Data = lADTFile.GetPointer<ENTRY_MDDF>(lCurrentPosition + 8);
+  auto const lMDDF_Data = lADTFile.GetPointer<ENTRY_MDDF>(lCurrentPosition + 8);
 
   if(world->mapIndex.sort_models_by_size_class())
   {
@@ -803,7 +806,7 @@ void MapTile::saveTile(World* world)
   lADTFile.GetPointer<MHDR>(lMHDR_Position + 8)->modf = lCurrentPosition - 0x14;
 
   // MODF data
-  ENTRY_MODF *lMODF_Data = lADTFile.GetPointer<ENTRY_MODF>(lCurrentPosition + 8);
+  auto const lMODF_Data = lADTFile.GetPointer<ENTRY_MODF>(lCurrentPosition + 8);
 
   lID = 0;
   for (auto const& object : lObjectInstances)
@@ -864,7 +867,7 @@ void MapTile::saveTile(World* world)
     SetChunkHeader(lADTFile, lCurrentPosition, 'MFBO', static_cast<int>(chunkSize));
     lADTFile.GetPointer<MHDR>(lMHDR_Position + 8)->mfbo = lCurrentPosition - 0x14;
 
-    int16_t *lMFBO_Data = lADTFile.GetPointer<int16_t>(lCurrentPosition + 8);
+    auto const lMFBO_Data = lADTFile.GetPointer<int16_t>(lCurrentPosition + 8);
 
     lID = 0;
 
@@ -883,9 +886,9 @@ void MapTile::saveTile(World* world)
     //! \todo check if nTexEffects == nTextures, correct order etc.
     lADTFile.Extend(8 + 4 * mTextureEffects.size());
     SetChunkHeader(lADTFile, lCurrentPosition, 'MTFX', 4 * mTextureEffects.size());
-    lADTFile.GetPointer<MHDR>(lMHDR_Position + 8)->mtfx = lCurrentPosition - 0x14;
+    lADTFile.GetPointer<MHDR>(lMHDR_Position + 8)->mtxf = lCurrentPosition - 0x14;
 
-    uint32_t* lMTFX_Data = lADTFile.GetPointer<uint32_t>(lCurrentPosition + 8);
+    auto const lMTFX_Data = lADTFile.GetPointer<uint32_t>(lCurrentPosition + 8);
 
     lID = 0;
     //they should be in the correct order...
@@ -898,13 +901,12 @@ void MapTile::saveTile(World* world)
   }
 #endif
 
-  lADTFile.Extend(static_cast<long>(lCurrentPosition - lADTFile.data.size())); // cleaning unused nulls at the end of file
-
-
   {
     BlizzardArchive::ClientFile f(_file_key.filepath(), Noggit::Application::NoggitApplication::instance()->clientData()
       , BlizzardArchive::ClientFile::NEW_FILE);
-    f.setBuffer(lADTFile.data);
+    // \todo This sounds wrong. There shouldn't *be* unused nulls to
+    // begin with.
+    f.setBuffer(lADTFile.data_up_to(lCurrentPosition)); // cleaning unused nulls at the end of file
     f.save();
   }
 
diff --git a/src/noggit/Misc.cpp b/src/noggit/Misc.cpp
index 0cc2d8fc..34f015ab 100755
--- a/src/noggit/Misc.cpp
+++ b/src/noggit/Misc.cpp
@@ -208,9 +208,9 @@ namespace misc
   }
 }
 
-void SetChunkHeader(sExtendableArray& pArray, int pPosition, int pMagix, int pSize)
+void SetChunkHeader(util::sExtendableArray& pArray, int pPosition, int pMagix, int pSize)
 {
-  sChunkHeader* Header = pArray.GetPointer<sChunkHeader>(pPosition);
+  auto const Header = pArray.GetPointer<sChunkHeader>(pPosition);
   Header->mMagic = pMagix;
   Header->mSize = pSize;
 }
diff --git a/src/noggit/Misc.h b/src/noggit/Misc.h
index 9677fca6..ca5d941a 100755
--- a/src/noggit/Misc.h
+++ b/src/noggit/Misc.h
@@ -13,6 +13,7 @@
 #include <glm/vec4.hpp>
 #include <glm/vec2.hpp>
 #include <noggit/Selection.h>
+#include <util/sExtendableArray.hpp>
 
 
 // namespace for static helper functions.
@@ -119,49 +120,11 @@ namespace misc
 
 //! \todo collect all lose functions/classes/structs for now, sort them later
 
-class sExtendableArray
-{
-public:
-  std::vector<char> data;
-
-	void Allocate (unsigned long pSize)
-	{
-    data.resize (pSize);
-	}
-
-	void Extend (long pAddition)
-	{
-    data.resize (data.size() + pAddition);
-	}
-
-  void Insert (unsigned long pPosition, unsigned long pAddition)
-	{
-    std::vector<char> tmp (pAddition);
-    data.insert (data.begin() + pPosition, tmp.begin(), tmp.end());
-  }
-
-	void Insert (unsigned long pPosition, unsigned long pAddition, const char * pAdditionalData)
-	{
-    data.insert (data.begin() + pPosition, pAdditionalData, pAdditionalData + pAddition);
-	}
-
-	template<typename To>
-	To * GetPointer(unsigned long pPosition = 0)
-	{
-		return(reinterpret_cast<To*>(data.data() + pPosition));
-	}
-
-  sExtendableArray() = default;
-	sExtendableArray(unsigned long pSize, const char *pData)
-    : data (pData, pData + pSize)
-	{}
-};
-
 struct sChunkHeader
 {
   int mMagic;
   int mSize;
 };
 
-void SetChunkHeader(sExtendableArray& pArray, int pPosition, int pMagix, int pSize = 0);
+void SetChunkHeader(util::sExtendableArray& pArray, int pPosition, int pMagix, int pSize = 0);
 
diff --git a/src/noggit/TileWater.cpp b/src/noggit/TileWater.cpp
index 29abc6a1..c0d6ae5f 100755
--- a/src/noggit/TileWater.cpp
+++ b/src/noggit/TileWater.cpp
@@ -59,7 +59,20 @@ void TileWater::autoGen(float factor)
   }
 }
 
-void TileWater::saveToFile(sExtendableArray &lADTFile, int &lMHDR_Position, int &lCurrentPosition)
+void TileWater::update_underground_vertices_depth()
+{
+  tagUpdate();
+
+  for (int z = 0; z < 16; ++z)
+  {
+    for (int x = 0; x < 16; ++x)
+    {
+      chunks[z][x]->update_underground_vertices_depth(tile->getChunk(x, z));
+    }
+  }
+}
+
+void TileWater::saveToFile(util::sExtendableArray &lADTFile, int &lMHDR_Position, int &lCurrentPosition)
 {
   if (!hasData(0))
   {
diff --git a/src/noggit/TileWater.hpp b/src/noggit/TileWater.hpp
index 398e922f..53b90d55 100755
--- a/src/noggit/TileWater.hpp
+++ b/src/noggit/TileWater.hpp
@@ -7,6 +7,7 @@
 #include <opengl/types.hpp>
 #include <noggit/rendering/LiquidTextureManager.hpp>
 #include <noggit/rendering/LiquidRender.hpp>
+#include <util/sExtendableArray.hpp>
 
 #include <memory>
 #include <vector>
@@ -15,7 +16,6 @@
 
 class MapTile;
 class liquid_layer;
-class sExtendableArray;
 enum LiquidLayerUpdateFlags;
 
 namespace BlizzardArchive
@@ -39,7 +39,7 @@ public:
   ChunkWater* getChunk(int x, int z);
 
   void readFromFile(BlizzardArchive::ClientFile& theFile, size_t basePos);
-  void saveToFile(sExtendableArray& lADTFile, int& lMHDR_Position, int& lCurrentPosition);
+  void saveToFile(util::sExtendableArray& lADTFile, int& lMHDR_Position, int& lCurrentPosition);
 
   void draw ( math::frustum const& frustum
             , const glm::vec3& camera
diff --git a/src/noggit/liquid_layer.cpp b/src/noggit/liquid_layer.cpp
index ca286182..efba81e8 100755
--- a/src/noggit/liquid_layer.cpp
+++ b/src/noggit/liquid_layer.cpp
@@ -261,7 +261,7 @@ void liquid_layer::create_vertices(float height)
     }
 }
 
-void liquid_layer::save(sExtendableArray& adt, int base_pos, int& info_pos, int& current_pos) const
+void liquid_layer::save(util::sExtendableArray& adt, int base_pos, int& info_pos, int& current_pos) const
 {
   int min_x = 9, min_z = 9, max_x = 0, max_z = 0;
   bool filled = true;
@@ -334,7 +334,7 @@ void liquid_layer::save(sExtendableArray& adt, int base_pos, int& info_pos, int&
     {
       for (int x = info.xOffset; x <= info.xOffset + info.width; ++x)
       {
-        memcpy(adt.GetPointer<char>(current_pos), &_vertices[z * 9 + x].position.y, sizeof(float));
+        memcpy(adt.GetPointer<char>(current_pos).get(), &_vertices[z * 9 + x].position.y, sizeof(float));
         current_pos += sizeof(float);
       }
     }
@@ -357,7 +357,7 @@ void liquid_layer::save(sExtendableArray& adt, int base_pos, int& info_pos, int&
         uv.x = static_cast<std::uint16_t>(std::min(_vertices[z * 9 + x].uv.x * 255.f, 65535.f));
         uv.y = static_cast<std::uint16_t>(std::min(_vertices[z * 9 + x].uv.y * 255.f, 65535.f));
 
-        memcpy(adt.GetPointer<char>(current_pos), &uv, sizeof(mh2o_uv));
+        memcpy(adt.GetPointer<char>(current_pos).get(), &uv, sizeof(mh2o_uv));
         current_pos += sizeof(mh2o_uv);
       }
     }
@@ -372,13 +372,13 @@ void liquid_layer::save(sExtendableArray& adt, int base_pos, int& info_pos, int&
       for (int x = info.xOffset; x <= info.xOffset + info.width; ++x)
       {
           std::uint8_t depth = static_cast<std::uint8_t>(std::min(_vertices[z * 9 + x].depth * 255.0f, 255.f));
-        memcpy(adt.GetPointer<char>(current_pos), &depth, sizeof(std::uint8_t));
+        memcpy(adt.GetPointer<char>(current_pos).get(), &depth, sizeof(std::uint8_t));
         current_pos += sizeof(std::uint8_t);
       }
     }
   }
 
-  memcpy(adt.GetPointer<char>(info_pos), &info, sizeof(MH2O_Information));
+  memcpy(adt.GetPointer<char>(info_pos).get(), &info, sizeof(MH2O_Information));
   info_pos += sizeof(MH2O_Information);
 }
 
diff --git a/src/noggit/liquid_layer.hpp b/src/noggit/liquid_layer.hpp
index a60dadf0..e6bff468 100755
--- a/src/noggit/liquid_layer.hpp
+++ b/src/noggit/liquid_layer.hpp
@@ -7,9 +7,9 @@
 #include <opengl/scoped.hpp>
 #include <array>
 #include <glm/vec2.hpp>
+#include <util/sExtendableArray.hpp>
 
 class MapChunk;
-class sExtendableArray;
 class ChunkWater;
 
 enum LiquidLayerUpdateFlags
@@ -59,7 +59,7 @@ public:
   liquid_layer& operator=(liquid_layer&&);
   liquid_layer& operator=(liquid_layer const& other);
 
-  void save(sExtendableArray& adt, int base_pos, int& info_pos, int& current_pos) const;
+  void save(util::sExtendableArray& adt, int base_pos, int& info_pos, int& current_pos) const;
 
   void update_attributes(MH2O_Attributes& attributes);
   void changeLiquidID(int id);
diff --git a/src/noggit/map_horizon.cpp b/src/noggit/map_horizon.cpp
index cb95fe38..4a085687 100755
--- a/src/noggit/map_horizon.cpp
+++ b/src/noggit/map_horizon.cpp
@@ -365,7 +365,7 @@ void map_horizon::save_wdl(World* world, bool regenerate)
     filename << "World\\Maps\\" << world->basename << "\\" << world->basename << ".wdl";
     //Log << "Saving WDL \"" << filename << "\"." << std::endl;
 
-    sExtendableArray wdlFile = sExtendableArray();
+    util::sExtendableArray wdlFile;
     int curPos = 0;
 
     // MVER
@@ -475,7 +475,7 @@ void map_horizon::save_wdl(World* world, bool regenerate)
     }
     BlizzardArchive::ClientFile f(filename.str(), Noggit::Application::NoggitApplication::instance()->clientData(),
     BlizzardArchive::ClientFile::NEW_FILE);
-    f.setBuffer(wdlFile.data);
+    f.setBuffer(wdlFile.all_data());
     f.save();
     f.close();
 
diff --git a/src/noggit/map_index.cpp b/src/noggit/map_index.cpp
index 7c59a3c6..039735b2 100755
--- a/src/noggit/map_index.cpp
+++ b/src/noggit/map_index.cpp
@@ -190,7 +190,7 @@ void MapIndex::save()
 
   //Log << "Saving WDT \"" << filename << "\"." << std::endl;
 
-  sExtendableArray wdtFile = sExtendableArray();
+  util::sExtendableArray wdtFile;
   int curPos = 0;
 
   // MVER
@@ -266,7 +266,7 @@ void MapIndex::save()
 
   BlizzardArchive::ClientFile f(filename.str(), Noggit::Application::NoggitApplication::instance()->clientData(),
                                 BlizzardArchive::ClientFile::NEW_FILE);
-  f.setBuffer(wdtFile.data);
+  f.setBuffer(wdtFile.all_data());
   f.save();
   f.close();
 
@@ -1240,7 +1240,7 @@ void MapIndex::create_empty_wdl() const
     filename << "World\\Maps\\" << basename << "\\" << basename << ".wdl"; // mapIndex.basename ? 
     //Log << "Saving WDL \"" << filename << "\"." << std::endl;
 
-    sExtendableArray wdlFile = sExtendableArray();
+    util::sExtendableArray wdlFile;
     int curPos = 0;
 
     // MVER
@@ -1340,7 +1340,7 @@ void MapIndex::create_empty_wdl() const
 
     BlizzardArchive::ClientFile f(filename.str(), Noggit::Application::NoggitApplication::instance()->clientData(),
     BlizzardArchive::ClientFile::NEW_FILE);
-    f.setBuffer(wdlFile.data);
+    f.setBuffer(wdlFile.all_data());
     f.save();
     f.close();
 }
diff --git a/src/util/sExtendableArray.cpp b/src/util/sExtendableArray.cpp
new file mode 100644
index 00000000..d5f00502
--- /dev/null
+++ b/src/util/sExtendableArray.cpp
@@ -0,0 +1,35 @@
+// This file is part of Noggit3, licensed under GNU General Public License (version 3).
+
+#include <util/sExtendableArray.hpp>
+
+namespace util
+{
+  void sExtendableArray::Extend (long pAddition)
+  {
+    data.resize (data.size() + pAddition);
+  }
+
+  void sExtendableArray::Insert (unsigned long pPosition, unsigned long pAddition)
+  {
+    std::vector<char> tmp (pAddition);
+    data.insert (data.begin() + pPosition, tmp.begin(), tmp.end());
+  }
+
+  void sExtendableArray::Insert (unsigned long pPosition, unsigned long pAddition, const char * pAdditionalData)
+  {
+    data.insert (data.begin() + pPosition, pAdditionalData, pAdditionalData + pAddition);
+  }
+
+  std::vector<char> sExtendableArray::all_data() const
+  {
+    return data_up_to (data.size());
+  }
+  std::vector<char> sExtendableArray::data_up_to (std::size_t position) const
+  {
+    return std::vector<char> (data.begin(), data.begin() + position);
+  }
+
+  sExtendableArray::sExtendableArray(unsigned long pSize, const char *pData)
+    : data (pData, pData + pSize)
+  {}
+}
diff --git a/src/util/sExtendableArray.hpp b/src/util/sExtendableArray.hpp
new file mode 100644
index 00000000..45383a84
--- /dev/null
+++ b/src/util/sExtendableArray.hpp
@@ -0,0 +1,52 @@
+// This file is part of Noggit3, licensed under GNU General Public License (version 3).
+
+#pragma once
+
+#include <vector>
+
+namespace util
+{
+  //! \todo This name is horrible. The API is mediocre.
+  class sExtendableArray
+  {
+    std::vector<char> data;
+
+  public:
+    //! Equivalent to `Allocate ($size + pAddition)`.
+    void Extend (long pAddition);
+
+    //! At \a pPosition, insert \a pAddition bytes that are all '\0',
+    //! moving existing data further back.
+    void Insert (unsigned long pPosition, unsigned long pAddition);
+
+    //! At \a pPosition, insert \a pAddition bytes with the data at \a
+    //! pAdditionalData, moving existing data further back.
+    void Insert (unsigned long pPosition, unsigned long pAddition, const char * pAdditionalData);
+
+    template<typename T>
+      struct LazyPointer
+    {
+      LazyPointer (std::vector<char>& data, std::size_t position);
+      T* get() const;
+      T& operator*() const;
+      T* operator->() const;
+      T& operator[] (std::size_t) const;
+      LazyPointer<T>& operator+= (std::size_t);
+
+    private:
+      std::vector<char>& _data;
+      std::size_t _position;
+    };
+
+    template<typename To>
+      LazyPointer<To> GetPointer(unsigned long pPosition = 0);
+
+    std::vector<char> all_data() const;
+    std::vector<char> data_up_to (std::size_t position) const;
+
+    sExtendableArray() = default;
+    sExtendableArray(unsigned long pSize, const char *pData);
+  };
+}
+
+#include <util/sExtendableArray.ipp>
diff --git a/src/util/sExtendableArray.ipp b/src/util/sExtendableArray.ipp
new file mode 100644
index 00000000..03807675
--- /dev/null
+++ b/src/util/sExtendableArray.ipp
@@ -0,0 +1,47 @@
+// This file is part of Noggit3, licensed under GNU General Public License (version 3).
+
+namespace util
+{
+  template<typename To>
+    sExtendableArray::LazyPointer<To> sExtendableArray::GetPointer
+      (unsigned long pPosition)
+  {
+    return {data, pPosition};
+  }
+
+  template<typename T>
+      sExtendableArray::LazyPointer<T>::LazyPointer
+        (std::vector<char>& data, std::size_t position)
+    : _data (data)
+    , _position (position)
+  {}
+
+  template<typename T>
+    T* sExtendableArray::LazyPointer<T>::get() const
+  {
+    return reinterpret_cast<T*> (_data.data() + _position);
+  }
+  template<typename T>
+    T& sExtendableArray::LazyPointer<T>::operator*() const
+  {
+    return *get();
+  }
+  template<typename T>
+    T* sExtendableArray::LazyPointer<T>::operator->() const
+  {
+    return get();
+  }
+  template<typename T>
+    T& sExtendableArray::LazyPointer<T>::operator[] (std::size_t i) const
+  {
+    return *(get() + i);
+  }
+
+  template<typename T>
+    sExtendableArray::LazyPointer<T>&
+      sExtendableArray::LazyPointer<T>::operator+= (std::size_t num)
+  {
+    _position += num * sizeof (T);
+    return *this;
+  }
+}