diff --git a/src/map.cpp b/src/map.cpp
index 5d6b79fb0..39f5e30fb 100644
--- a/src/map.cpp
+++ b/src/map.cpp
@@ -1763,6 +1763,11 @@ void Map::transformLiquidsFinite(std::map<v3s16, MapBlock*> & modified_blocks)
 			total_level = LIQUID_LEVEL_SOURCE * can_liquid_same_level; 
 		}
 
+		// prevent lakes in air under unloaded blocks
+		if (p0.Y > water_level && neighbors[D_BOTTOM].n.getContent() == CONTENT_IGNORE) {
+			total_level = 0;
+		}
+
 		// calculate self level 5 blocks
 		u8 want_level = 
 			  total_level >= LIQUID_LEVEL_SOURCE * can_liquid_same_level
@@ -1807,8 +1812,8 @@ void Map::transformLiquidsFinite(std::map<v3s16, MapBlock*> & modified_blocks)
 		}
 
 		for (u16 ii = 0; ii < 7; ii++) // infinity and cave flood optimization
-			if (liquid_levels_want[ii] >= 0 &&
-				(neighbors[ii].i ||
+			if (    neighbors[ii].i ||
+				(liquid_levels_want[ii] >= 0 &&
 				 (fast_flood && p0.Y < water_level &&
 				  (initial_size >= 1000
 				   && ii != D_TOP
@@ -1916,8 +1921,7 @@ void Map::transformLiquidsFinite(std::map<v3s16, MapBlock*> & modified_blocks)
 
 			if(!suspect.empty()){
 				// Blame suspect
-				RollbackScopeActor rollback_scope(m_gamedef->rollback(),
-													suspect, true);
+				RollbackScopeActor rollback_scope(m_gamedef->rollback(), suspect, true);
 				// Get old node for rollback
 				RollbackNode rollback_oldnode(this, p0, m_gamedef);
 				// Set node
diff --git a/src/mapgen_indev.cpp b/src/mapgen_indev.cpp
index 5d455827a..5c842b6a5 100644
--- a/src/mapgen_indev.cpp
+++ b/src/mapgen_indev.cpp
@@ -265,9 +265,9 @@ void MapgenIndev::defineCave(Cave & cave, PseudoRandom ps, v3s16 node_min, bool
 		cave.part_max_length_rs = ps.range(2,4);
 		if (node_min.Y < -100 && !ps.range(0, farscale(0.2, node_min.X,node_min.Y,node_min.Z)*30)) { //huge
 			cave.flooded = !ps.range(0, 3);
-			cave.tunnel_routepoints = ps.range(5, 20);
+			cave.tunnel_routepoints = ps.range(5, 30);
 			cave.min_tunnel_diameter = 30;
-			cave.max_tunnel_diameter = ps.range(40, ps.range(80,120));
+			cave.max_tunnel_diameter = ps.range(40, ps.range(80,200));
 		} else {
 			cave.tunnel_routepoints = ps.range(5, ps.range(15,30));
 			cave.min_tunnel_diameter = 5;