diff -ruN freeciv.orig/data/civ1/terrain.ruleset freeciv/data/civ1/terrain.ruleset
--- freeciv.orig/data/civ1/terrain.ruleset	Mon Apr 17 12:53:14 2000
+++ freeciv/data/civ1/terrain.ruleset	Sat Jun 17 21:58:55 2000
@@ -84,6 +84,7 @@
 ; Notes:
 ;
 ; terrain_name         = name as seen by user; if "unused", it is not used
+; flags                = one of "Land" or "Ocean", and maybe "SweetWater"
 ; graphic              = preferred base graphics tag in tilespec; must have
 ;                        tags with extensions _n0s0e0e0 etc.
 ; graphic_alt          = alternate graphics tag if preferred is not found;
@@ -129,6 +130,7 @@
 
 [terrain_arctic]
 terrain_name         = _("Arctic")
+flags		     = "Land"
 graphic              = "t.arctic"
 graphic_alt	     = "-"
 movement_cost        = 2
@@ -166,6 +168,7 @@
 
 [terrain_desert]
 terrain_name         = _("Desert")
+flags		     = "Land"
 graphic              = "t.desert"
 graphic_alt	     = "-"
 movement_cost        = 1
@@ -202,6 +205,7 @@
 
 [terrain_forest]
 terrain_name         = _("Forest")
+flags		     = "Land"
 graphic              = "t.forest"
 graphic_alt	     = "-"
 movement_cost        = 2
@@ -238,6 +242,7 @@
 
 [terrain_grassland]
 terrain_name         = _("Grassland")
+flags		     = "Land"
 graphic              = "t.grassland"
 graphic_alt	     = "-"
 movement_cost        = 1
@@ -273,6 +278,7 @@
 
 [terrain_hills]
 terrain_name         = _("Hills")
+flags		     = "Land"
 graphic              = "t.hills"
 graphic_alt	     = "-"
 movement_cost        = 2
@@ -309,6 +315,7 @@
 
 [terrain_jungle]
 terrain_name         = _("Jungle")
+flags		     = "Land"
 graphic              = "t.jungle"
 graphic_alt	     = "-"
 movement_cost        = 2
@@ -345,6 +352,7 @@
 
 [terrain_mountains]
 terrain_name         = _("Mountains")
+flags		     = "Land"
 graphic              = "t.mountains"
 graphic_alt	     = "-"
 movement_cost        = 3
@@ -381,6 +389,7 @@
 
 [terrain_ocean]
 terrain_name         = _("Ocean")
+flags		     = "Ocean", "SweetWater"
 graphic              = "t.ocean"
 graphic_alt	     = "-"
 movement_cost        = 1
@@ -419,6 +428,7 @@
 
 [terrain_plains]
 terrain_name         = _("Plains")
+flags		     = "Land"
 graphic              = "t.plains"
 graphic_alt	     = "-"
 movement_cost        = 1
@@ -455,6 +465,7 @@
 
 [terrain_river]
 terrain_name         = _("River")
+flags		     = "Land", "SweetWater"
 graphic              = "t.t_river"
 graphic_alt	     = "-"
 movement_cost        = 1
@@ -494,6 +505,7 @@
 
 [terrain_swamp]
 terrain_name         = _("Swamp")
+flags		     = "Land"
 graphic              = "t.swamp"
 graphic_alt	     = "-"
 movement_cost        = 2
@@ -530,6 +542,7 @@
 
 [terrain_tundra]
 terrain_name         = _("Tundra")
+flags		     = "Land"
 graphic              = "t.tundra"
 graphic_alt	     = "-"
 movement_cost        = 1
diff -ruN freeciv.orig/data/civ2/terrain.ruleset freeciv/data/civ2/terrain.ruleset
--- freeciv.orig/data/civ2/terrain.ruleset	Mon Apr 17 12:53:14 2000
+++ freeciv/data/civ2/terrain.ruleset	Sat Jun 17 22:03:01 2000
@@ -92,6 +92,7 @@
 ; Notes:
 ;
 ; terrain_name         = name as seen by user; if "unused", it is not used
+; flags                = one of "Land" or "Ocean", and maybe "SweetWater"
 ; graphic              = preferred base graphics tag in tilespec; must have
 ;                        tags with extensions _n0s0e0e0 etc.
 ; graphic_alt          = alternate graphics tag if preferred is not found;
@@ -137,6 +138,7 @@
 
 [terrain_glacier]
 terrain_name         = _("Glacier")
+flags		     = "Land"
 graphic              = "t.arctic"
 graphic_alt	     = "-"
 movement_cost        = 2
@@ -174,6 +176,7 @@
 
 [terrain_desert]
 terrain_name         = _("Desert")
+flags		     = "Land"
 graphic              = "t.desert"
 graphic_alt	     = "-"
 movement_cost        = 1
@@ -210,6 +213,7 @@
 
 [terrain_forest]
 terrain_name         = _("Forest")
+flags		     = "Land"
 graphic              = "t.forest"
 graphic_alt	     = "-"
 movement_cost        = 2
@@ -246,6 +250,7 @@
 
 [terrain_grassland]
 terrain_name         = _("Grassland")
+flags		     = "Land"
 graphic              = "t.grassland"
 graphic_alt	     = "-"
 movement_cost        = 1
@@ -281,6 +286,7 @@
 
 [terrain_hills]
 terrain_name         = _("Hills")
+flags		     = "Land"
 graphic              = "t.hills"
 graphic_alt	     = "-"
 movement_cost        = 2
@@ -317,6 +323,7 @@
 
 [terrain_jungle]
 terrain_name         = _("Jungle")
+flags		     = "Land"
 graphic              = "t.jungle"
 graphic_alt	     = "-"
 movement_cost        = 2
@@ -353,6 +360,7 @@
 
 [terrain_mountains]
 terrain_name         = _("Mountains")
+flags		     = "Land"
 graphic              = "t.mountains"
 graphic_alt	     = "-"
 movement_cost        = 3
@@ -389,6 +397,7 @@
 
 [terrain_ocean]
 terrain_name         = _("Ocean")
+flags		     = "Ocean", "SweetWater"
 graphic              = "t.ocean"
 graphic_alt	     = "-"
 movement_cost        = 1
@@ -427,6 +436,7 @@
 
 [terrain_plains]
 terrain_name         = _("Plains")
+flags		     = "Land"
 graphic              = "t.plains"
 graphic_alt	     = "-"
 movement_cost        = 1
@@ -463,6 +473,7 @@
 
 [terrain_unused_0]
 terrain_name         = "unused"
+flags		     = "Land"
 graphic              = "-"
 graphic_alt	     = "-"
 movement_cost        = 0
@@ -495,6 +506,7 @@
 
 [terrain_swamp]
 terrain_name         = _("Swamp")
+flags		     = "Land"
 graphic              = "t.swamp"
 graphic_alt	     = "-"
 movement_cost        = 2
@@ -531,6 +543,7 @@
 
 [terrain_tundra]
 terrain_name         = _("Tundra")
+flags		     = "Land"
 graphic              = "t.tundra"
 graphic_alt	     = "-"
 movement_cost        = 1
diff -ruN freeciv.orig/data/default/terrain.ruleset freeciv/data/default/terrain.ruleset
--- freeciv.orig/data/default/terrain.ruleset	Wed Apr 26 12:53:06 2000
+++ freeciv/data/default/terrain.ruleset	Sat Jun 17 22:04:16 2000
@@ -92,6 +92,7 @@
 ; Notes:
 ;
 ; terrain_name         = name as seen by user; if "unused", it is not used
+; flags                = one of "Land" or "Ocean", and maybe "SweetWater"
 ; graphic              = preferred base graphics tag in tilespec; must have
 ;                        tags with extensions _n0s0e0e0 etc.
 ; graphic_alt          = alternate graphics tag if preferred is not found;
@@ -137,6 +138,7 @@
 
 [terrain_glacier]
 terrain_name         = _("Glacier")
+flags		     = "Land"
 graphic              = "t.arctic"
 graphic_alt	     = "-"
 movement_cost        = 2
@@ -174,6 +176,7 @@
 
 [terrain_desert]
 terrain_name         = _("Desert")
+flags		     = "Land"
 graphic              = "t.desert"
 graphic_alt	     = "-"
 movement_cost        = 1
@@ -210,6 +213,7 @@
 
 [terrain_forest]
 terrain_name         = _("Forest")
+flags		     = "Land"
 graphic              = "t.forest"
 graphic_alt	     = "-"
 movement_cost        = 2
@@ -246,6 +250,7 @@
 
 [terrain_grassland]
 terrain_name         = _("Grassland")
+flags		     = "Land"
 graphic              = "t.grassland"
 graphic_alt	     = "-"
 movement_cost        = 1
@@ -281,6 +286,7 @@
 
 [terrain_hills]
 terrain_name         = _("Hills")
+flags		     = "Land"
 graphic              = "t.hills"
 graphic_alt	     = "-"
 movement_cost        = 2
@@ -317,6 +323,7 @@
 
 [terrain_jungle]
 terrain_name         = _("Jungle")
+flags		     = "Land"
 graphic              = "t.jungle"
 graphic_alt	     = "-"
 movement_cost        = 2
@@ -353,6 +360,7 @@
 
 [terrain_mountains]
 terrain_name         = _("Mountains")
+flags		     = "Land"
 graphic              = "t.mountains"
 graphic_alt	     = "-"
 movement_cost        = 3
@@ -389,6 +397,7 @@
 
 [terrain_ocean]
 terrain_name         = _("Ocean")
+flags		     = "Ocean", "SweetWater"
 graphic              = "t.ocean"
 graphic_alt	     = "-"
 movement_cost        = 1
@@ -427,6 +436,7 @@
 
 [terrain_plains]
 terrain_name         = _("Plains")
+flags		     = "Land"
 graphic              = "t.plains"
 graphic_alt	     = "-"
 movement_cost        = 1
@@ -463,6 +473,7 @@
 
 [terrain_unused_0]
 terrain_name         = "unused"
+flags		     = "Land"
 graphic              = "-"
 graphic_alt	     = "-"
 movement_cost        = 0
@@ -495,6 +506,7 @@
 
 [terrain_swamp]
 terrain_name         = _("Swamp")
+flags		     = "Land"
 graphic              = "t.swamp"
 graphic_alt	     = "-"
 movement_cost        = 2
@@ -531,6 +543,7 @@
 
 [terrain_tundra]
 terrain_name         = _("Tundra")
+flags		     = "Land"
 graphic              = "t.tundra"
 graphic_alt	     = "-"
 movement_cost        = 1