--- freeciv-phased/common/combat.c.old	Tue Mar 12 11:55:03 2002
+++ freeciv-phased/common/combat.c	Tue Mar 12 13:20:43 2002
@@ -446,8 +446,9 @@
 have anything to do with the value of a unit.
 It would be nice if the function was a bit more fuzzy about prioritizing,
 making it able to fx choose a 1a/9d unit over a 10a/10d unit. It should
-also be able to spare units without full hp's to some extend, as these
+also be able to spare units without full hp's to some extent, as these
 could be more valuable later.
+A seaborne unit must attempt to defend a city against submarine attacks.
 **************************************************************************/
 struct unit *get_defender(struct unit *attacker, int x, int y)
 {
@@ -466,6 +467,13 @@
 
       /* This will make units roughly evenly good defenders look alike. */
       int unit_def = (int) (100000 * (1 - unit_win_chance(attacker, defender)));
+      /* Ensure that seaborne units that can only attack other seaborne
+         units can actually attack enemy seaborne units in a stack if
+         they are present, and not fail because the enemy chose to
+         defend with a ground unit. Go, subs, go! {:-) - Per */
+      if (unit_flag(attacker, F_NO_LAND_ATTACK)
+          && is_sailing_unit(defender))
+              unit_def += 100000;
       assert(unit_def >= 0);
 
       if (unit_def > bestvalue) {
--- freeciv-phased/server/unittools.c.old	Tue Mar 12 11:49:18 2002
+++ freeciv-phased/server/unittools.c	Tue Mar 12 13:25:32 2002
@@ -139,7 +139,9 @@
     return FALSE;
   }
 
-  if (unit_flag(punit, F_NO_LAND_ATTACK) && totile!=T_OCEAN)  {
+  /* no_land_attack units can only attack seaborne units */
+  if ((unit_flag(punit, F_NO_LAND_ATTACK))
+      && (!is_sailing_unit(pdefender))) {
     return FALSE;
   }