diff --git a/return_to_ship.py b/return_to_ship.py
index b7c196a..bd0990d 100644
--- a/return_to_ship.py
+++ b/return_to_ship.py
@@ -11,6 +11,7 @@ from datetime import timedelta
 from fancy_printing import print_fancy
 
 CHEST_TIMER_FILE = "adventure/seafloor/coral_reef/.timer"
+LOG_FILE = ".log"
 BEGINNING = [
     "Your adventure has only just begun. You are not yet ready to return to the ship. More secrets await you in the ocean's depths. Use `ls` to look around, and use `cd adventure` to start the adventure..."
 ]
@@ -35,6 +36,8 @@ def reset():
 
 def win():
     print_fancy(VICTORY)
+    win_time = datetime.now().isoformat()
+    Path(LOG_FILE).write_text(f"finished the lab at {win_time}\n")
 
 def chest_was_opened():
     return Path(CHEST_TIMER_FILE).exists()