diff --git a/src/core/execution/NationExecution.ts b/src/core/execution/NationExecution.ts
index 4a836eec2..030a2bc89 100644
--- a/src/core/execution/NationExecution.ts
+++ b/src/core/execution/NationExecution.ts
@@ -14,6 +14,7 @@ import {
   UnitType,
 } from "../game/Game";
 import { TileRef, euclDistFN } from "../game/GameMap";
+import { canBuildTransportShip } from "../game/TransportShipUtils";
 import { PseudoRandom } from "../PseudoRandom";
 import { GameID } from "../Schemas";
 import { boundingBoxTiles, calculateBoundingBox, simpleHash } from "../Util";
@@ -501,6 +502,7 @@ export class NationExecution implements Execution {
     if (this.player === null) throw new Error("not initialized");
     const x = this.mg.x(tile);
     const y = this.mg.y(tile);
+    const unreachablePlayers = new Set<PlayerID>();
     for (let i = 0; i < 500; i++) {
       const randX = this.random.nextInt(x - 150, x + 150);
       const randY = this.random.nextInt(y - 150, y + 150);
@@ -515,6 +517,10 @@ export class NationExecution implements Execution {
       if (owner === this.player) {
         continue;
       }
+      // Skip players we already know are unreachable (Performance optimization)
+      if (owner.isPlayer() && unreachablePlayers.has(owner.id())) {
+        continue;
+      }
       // Don't send boats to players with which we share a border, that usually looks stupid
       if (owner.isPlayer() && borderingEnemies.includes(owner)) {
         continue;
@@ -523,17 +529,28 @@ export class NationExecution implements Execution {
       if (owner.isPlayer() && owner.troops() > this.player.troops() * 2) {
         continue;
       }
-      // High-interest targeting: prioritize unowned tiles or tiles owned by bots
+
+      let matchesCriteria = false;
       if (highInterestOnly) {
-        if (!owner.isPlayer() || owner.type() === PlayerType.Bot) {
-          return randTile;
-        }
+        // High-interest targeting: prioritize unowned tiles or tiles owned by bots
+        matchesCriteria = !owner.isPlayer() || owner.type() === PlayerType.Bot;
       } else {
         // Normal targeting: return unowned tiles or tiles owned by non-friendly players
-        if (!owner.isPlayer() || !owner.isFriendly(this.player)) {
-          return randTile;
-        }
+        matchesCriteria = !owner.isPlayer() || !owner.isFriendly(this.player);
       }
+      if (!matchesCriteria) {
+        continue;
+      }
+
+      // Validate that we can actually build a transport ship to this target
+      if (canBuildTransportShip(this.mg, this.player, randTile) === false) {
+        if (owner.isPlayer()) {
+          unreachablePlayers.add(owner.id());
+        }
+        continue;
+      }
+
+      return randTile;
     }
     return null;
   }