Patrol Boat

Test Chamber 13: Place portals as shown in the image. Use a portal to move the laser sideways and a time portal to send it into the future. You can take some laser damage to travel into the future. Once in the future, rearrange portals without affecting the present. Align the laser directly into the target to exit the chamber.

Test Chamber 14: Start by taking a time portal to the present. Summon a reflector cube and position it in the present as indicated. Use a portal to bring a laser through the first node, then use it to reflect the laser into the next two nodes. Travel to the future. Use portals to bring a laser into the present through the time portal, ensuring it passes through the node. Retrieve the reflector cube from the future and bring it to the present via a time portal. Ensure the present reflector cube hits all three nodes; adjust as needed. If the cube was moved, return to the future to retrieve it again. Finally, place the future reflector cube to reflect the laser into the receiver, completing the chamber.

Test Chamber 15: This chamber involves frequent time portal use. Begin by passing through the particle field to the left. Place a portal where the laser hits the wall and a time portal on the opposite wall. Travel through the time portal to reach the future, bypassing the particle field. Proceed to the other side of the room and use another time portal to return to the present, now on the other side of the field. Place a new portal on the upper wall above the laser room so the laser hits the first receiver. Return to the future and place a portal on the small wall in the laser room to shoot the receiver. Go back to the present; the laser should still be hitting the first receiver, powering an elevating platform. Stand on the platform and shoot a time portal behind the node to raise it, allowing you to summon a reflector cube. Place this cube on the lip above the second receiver. Travel to the future. Retrieve the future reflector cube and bring it back to the present via a time portal within the laser room, positioning it to reflect the laser into the second receiver through the node. To reach the other side of the particle field without traversing it, use a portal on the far side or a time portal. Once in the present on the other side, climb the stairs and use a portal on the upper wall to hit the third receiver. Move the reflector cube onto the switch to complete the chamber.