diff --git a/src/main/java/biomesoplenty/common/init/ModBiomes.java b/src/main/java/biomesoplenty/common/init/ModBiomes.java
index 6c4241365..f0b476cb4 100644
--- a/src/main/java/biomesoplenty/common/init/ModBiomes.java
+++ b/src/main/java/biomesoplenty/common/init/ModBiomes.java
@@ -198,7 +198,7 @@ public class ModBiomes implements BOPBiomes.IBiomeRegistry
     public static Map<Integer, List<Integer>> subBiomesMap;
     public static Map<Integer, List<Integer>> mutatedBiomesMap;
     
-    public static ArrayList<WeightedBiomeEntry> islandBiomesList = new ArrayList<WeightedBiomeEntry>();
+    public static Map<Integer, Integer> islandBiomesMap = new HashMap<Integer, Integer>();
     public static int totalIslandBiomesWeight;
     
     public static void init()
@@ -396,14 +396,16 @@ public class ModBiomes implements BOPBiomes.IBiomeRegistry
         canyon_ravine = registerBOPBiome(new BiomeGenCanyon(BiomeGenCanyon.CanyonType.RAVINE), "Canyon Ravine");
         coral_reef = registerBOPBiome(new BiomeGenCoralReef(), "Coral Reef");
         kelp_forest = registerBOPBiome(new BiomeGenKelpForest(), "Kelp Forest");
-        tropical_island = registerBOPBiome(new BiomeGenTropicalIsland(), "Tropical Island");
-        
+
         setSubBiome(canyon, canyon_ravine);
         setSubBiome(Optional.of(BiomeGenBase.ocean), BOPBiomes.coral_reef);
         setSubBiome(Optional.of(BiomeGenBase.ocean), BOPBiomes.kelp_forest);
 
         // island biomes
         
+        tropical_island = registerBOPBiome(new BiomeGenTropicalIsland(), "Tropical Island");
+    
+        addIslandBiome(tropical_island, 10);
     }
     
     private static void registerBiomeDictionaryTags()
@@ -574,10 +576,13 @@ public class ModBiomes implements BOPBiomes.IBiomeRegistry
         }
     }
     
-    private static void addIslandBiome(BiomeGenBase biome, int weight)
+    private static void addIslandBiome(Optional<BiomeGenBase> biome, int weight)
     {
-        totalIslandBiomesWeight += weight;
-        islandBiomesList.add(new WeightedBiomeEntry(weight, biome));
+        if (biome.isPresent())
+        {
+            totalIslandBiomesWeight += weight;
+            islandBiomesMap.put(biome.get().biomeID, weight);
+        }
     }
     
     private static void configureBiome(IExtendedBiome biome, String idName)
diff --git a/src/main/java/biomesoplenty/common/world/layer/GenLayerBiomeBOP.java b/src/main/java/biomesoplenty/common/world/layer/GenLayerBiomeBOP.java
index 9ff058fff..8121599d6 100644
--- a/src/main/java/biomesoplenty/common/world/layer/GenLayerBiomeBOP.java
+++ b/src/main/java/biomesoplenty/common/world/layer/GenLayerBiomeBOP.java
@@ -13,6 +13,7 @@ import net.minecraft.world.gen.layer.GenLayer;
 import net.minecraft.world.gen.layer.IntCache;
 import net.minecraftforge.common.BiomeManager.BiomeType;
 import biomesoplenty.common.enums.BOPClimates;
+import biomesoplenty.common.init.ModBiomes;
 import biomesoplenty.common.world.BOPWorldSettings;
 
 public class GenLayerBiomeBOP extends BOPGenLayer
@@ -55,10 +56,10 @@ public class GenLayerBiomeBOP extends BOPGenLayer
                 {
                     out[index] = climate.getRandomOceanBiome(this, true).biomeID;
                 }
-                else if (landSeaVal == BiomeGenBase.mushroomIsland.biomeID && climate.biomeType != BiomeType.ICY)
+                else if ((landSeaVal == BiomeGenBase.mushroomIsland.biomeID || ModBiomes.islandBiomesMap.containsKey(landSeaVal)) && climate.biomeType != BiomeType.ICY)
                 {
-                    // keep mushroom islands, unless it's in an icy climate in which case, replace
-                    out[index] = BiomeGenBase.mushroomIsland.biomeID;
+                    // keep islands, unless it's in an icy climate in which case, replace
+                    out[index] = landSeaVal;
                 }
                 else if (landSeaVal == 0)
                 {
diff --git a/src/main/java/biomesoplenty/common/world/layer/GenLayerLargeIsland.java b/src/main/java/biomesoplenty/common/world/layer/GenLayerLargeIsland.java
index 923a8990d..c68b8074d 100644
--- a/src/main/java/biomesoplenty/common/world/layer/GenLayerLargeIsland.java
+++ b/src/main/java/biomesoplenty/common/world/layer/GenLayerLargeIsland.java
@@ -8,6 +8,7 @@
 package biomesoplenty.common.world.layer;
 
 import java.util.Iterator;
+import java.util.Map.Entry;
 
 import biomesoplenty.common.enums.BOPClimates.WeightedBiomeEntry;
 import biomesoplenty.common.init.ModBiomes;
@@ -42,7 +43,7 @@ public class GenLayerLargeIsland extends BOPGenLayer
 
                 this.initChunkSeed((long)(x + areaX), (long)(z + areaY));
 
-                if (centerVal == 0 && northWestVal == 0 && northEastVal == 0 && southWestVal == 0 && southEastVal == 0 && this.nextInt(50) == 0)
+                if (centerVal == 0 && northWestVal == 0 && northEastVal == 0 && southWestVal == 0 && southEastVal == 0 && this.nextInt(75) == 0)
                 {
                     out[x + z * areaWidth] = getRandomIslandBiome();
                 }
@@ -59,14 +60,15 @@ public class GenLayerLargeIsland extends BOPGenLayer
     public int getRandomIslandBiome()
     {
         int weight = this.nextInt(ModBiomes.totalIslandBiomesWeight);
-        Iterator<WeightedBiomeEntry> iterator = ModBiomes.islandBiomesList.iterator();
-        WeightedBiomeEntry item;
+        Iterator<Entry<Integer, Integer>> iterator = ModBiomes.islandBiomesMap.entrySet().iterator();
+        
+        Entry<Integer, Integer> item;
         do
         {
             item = iterator.next();
-            weight -= item.weight;
+            weight -= item.getValue();
         }
         while (weight >= 0);
-        return item.biome.biomeID;
+        return item.getKey();
     }
 }