diff --git a/core/src/com/unciv/logic/civilization/CivilizationInfo.kt b/core/src/com/unciv/logic/civilization/CivilizationInfo.kt
index bc78a89295..0f92794084 100644
--- a/core/src/com/unciv/logic/civilization/CivilizationInfo.kt
+++ b/core/src/com/unciv/logic/civilization/CivilizationInfo.kt
@@ -64,7 +64,7 @@ class CivilizationInfo {
         toReturn.scienceVictory = scienceVictory.clone()
         toReturn.diplomacy.putAll(diplomacy.values.map { it.clone() }.associateBy { it.otherCivName })
         toReturn.cities = cities.map { it.clone() }
-        toReturn.exploredTiles.addAll(exploredTiles)
+        toReturn.exploredTiles.addAll(exploredTiles.toList()) // we actually fot a concurrent modification exception here, the toList should solve that
         return toReturn
     }
 
diff --git a/core/src/com/unciv/ui/worldscreen/unit/UnitActions.kt b/core/src/com/unciv/ui/worldscreen/unit/UnitActions.kt
index 6fa04269c0..29bdc07327 100644
--- a/core/src/com/unciv/ui/worldscreen/unit/UnitActions.kt
+++ b/core/src/com/unciv/ui/worldscreen/unit/UnitActions.kt
@@ -41,7 +41,7 @@ class UnitActions {
             },true)
         }
 
-        if(!unit.baseUnit().unitType.isCivilian() && !unit.isEmbarked()
+        if(!unit.baseUnit().unitType.isCivilian() && !unit.isEmbarked() && !unit.baseUnit.unitType.isWaterUnit()
                 && !unit.hasUnique("No defensive terrain bonus") && !unit.isFortified()) {
             actionList += UnitAction("Fortify", { unit.action = "Fortify 0" }, unit.currentMovement != 0f)
         }