diff -ruN freeciv.orig/common/map.c freeciv/common/map.c
--- freeciv.orig/common/map.c	Wed Jun 14 13:17:52 2000
+++ freeciv/common/map.c	Sat Jun 17 20:04:32 2000
@@ -547,6 +547,25 @@
 }
 
 /***************************************************************
+Check if terrain is ok for land units to be,
+infrastructure (transporters etc.) doesn't count
+
+currently always : ((is_land(x,y) && is_ocean(x,y)) == 0)
+but may change in future (T_ARCHIPELAGO, T_FJORD etc.)
+***************************************************************/
+int is_land (int x, int y) {
+  return (map_get_terrain(x,y) != T_OCEAN);
+}
+
+/***************************************************************
+Check if terrain is ok for sea units to be,
+infrastructure (cities etc.) doesn't count
+***************************************************************/
+int is_ocean (int x, int y) {
+  return (map_get_terrain(x,y) == T_OCEAN);
+}
+
+/***************************************************************
 ...
 ***************************************************************/
 int get_tile_food_base(struct tile * ptile)
diff -ruN freeciv.orig/common/map.h freeciv/common/map.h
--- freeciv.orig/common/map.h	Wed Jun 14 13:17:53 2000
+++ freeciv/common/map.h	Sat Jun 17 19:58:57 2000
@@ -217,6 +217,8 @@
 int is_special_close(int x, int y);
 int is_special_type_close(int x, int y, enum tile_special_type spe);
 int is_sea_usable(int x, int y);
+int is_land (int x, int y);
+int is_ocean (int x, int y);
 int get_tile_food_base(struct tile * ptile);
 int get_tile_shield_base(struct tile * ptile);
 int get_tile_trade_base(struct tile * ptile);