diff --git a/docs/landscape_grid.html b/docs/landscape_grid.html
index b2ee8293e2..d7c7326aa1 100644
--- a/docs/landscape_grid.html
+++ b/docs/landscape_grid.html
@@ -246,7 +246,7 @@ the array so you can quickly see what is used and what is not.
       <td class="bits" rowspan=4><span class="free">OOOO OOOO OOOO OOOO</span></td>
       <td class="bits" rowspan=5><span class="free">OOOO OOO</span><span class="used" title="Non-flooding state">X</span></td>
       <td class="bits"><span class="free">OOOO OOOO</span></td>
-      <td class="bits"><span class="used" title="Water tile type: coast, clear, lock, depot">0000</span> <span class="free">OOO0</span></td>
+      <td class="bits"><span class="free">OO</span><span class="used" title="Water tile type: 0 (Clear)">XX</span> <span class="free">OOOO</span></td>
       <td class="bits" rowspan=5><span class="free">OOOO OOOO</span></td>
       <td class="bits" rowspan=5><span class="free">OOOO OOOO</span></td>
       <td class="bits" rowspan=5><span class="free">OOOO OOOO OOOO OOOO</span></td>
@@ -254,23 +254,23 @@ the array so you can quickly see what is used and what is not.
     <tr>
       <td class="caption">canal, river</td>
       <td class="bits"><span class="used" title="Canal/river random bits">XXXX XXXX</span></td>
-      <td class="bits"><span class="used" title="Water tile type: coast, clear, lock, depot">0000</span> <span class="free">OOOO</span></td>
+      <td class="bits"><span class="free">OO</span><span class="used" title="Water tile type: 0 (Clear)">XX</span> <span class="free">OOOO</span></td>
     </tr>
     <tr>
       <td class="caption">shore</td>
       <td class="bits"><span class="free">OOOO OOOO</span></td>
-      <td class="bits"><span class="used" title="Water tile type: coast, clear, lock, depot">0001</span> <span class="free">OOOO</span></td>
+      <td class="bits"><span class="free">OO</span><span class="used" title="Water tile type: 1 (Coast)">XX</span> <span class="free">OOOO</span></td>
     </tr>
     <tr>
       <td class="caption">lock</td>
       <td class="bits"><span class="free">OOOO OOOO</span></td>
-      <td class="bits"><span class="used" title="Water tile type: coast, clear, lock, depot">0010</span> <span class="used" title="Lock part">XX</span><span class="used" title="Lock orientation m5[1..0]">XX</span></td>
+      <td class="bits"><span class="free">OO</span><span class="used" title="Water tile type: 2 (Lock)">XX</span> <span class="used" title="Lock part">XX</span><span class="used" title="Lock orientation m5[1..0]">XX</span></td>
     </tr>
     <tr>
       <td class="caption">shipdepot</td>
       <td class="bits"><span class="pool" title="Depot index on pool">XXXX XXXX XXXX XXXX</span></td>
       <td class="bits"><span class="free">OOOO OOOO</span></td>
-      <td class="bits"><span class="used" title="Water tile type: coast, clear, lock, depot">0011</span> <span class="free">OO</span><span class="used" title="Depot axis">X</span><span class="used" title="Depot part">X</span></td>
+      <td class="bits"><span class="free">OO</span><span class="used" title="Water tile type: 3 (Depot)">XX</span> <span class="free">OO</span><span class="used" title="Depot axis">X</span><span class="used" title="Depot part">X</span></td>
     </tr>
     <tr>
       <td rowspan=2>8</td>
diff --git a/src/water_map.h b/src/water_map.h
index c21029b670..bdc245f999 100644
--- a/src/water_map.h
+++ b/src/water_map.h
@@ -17,7 +17,7 @@
  * Bit field layout of m5 for water tiles.
  */
 static constexpr uint8_t WBL_TYPE_BEGIN = 4; ///< Start of the 'type' bitfield.
-static constexpr uint8_t WBL_TYPE_COUNT = 4; ///< Length of the 'type' bitfield.
+static constexpr uint8_t WBL_TYPE_COUNT = 2; ///< Length of the 'type' bitfield.
 
 static constexpr uint8_t WBL_LOCK_ORIENT_BEGIN = 0; ///< Start of lock orientation bitfield.
 static constexpr uint8_t WBL_LOCK_ORIENT_COUNT = 2; ///< Length of lock orientation bitfield.