diff --git a/src/templates/apps/gameboard/my_sea.html b/src/templates/apps/gameboard/my_sea.html
index a4cf43e..5183385 100644
--- a/src/templates/apps/gameboard/my_sea.html
+++ b/src/templates/apps/gameboard/my_sea.html
@@ -663,9 +663,16 @@
                                 return;
                             }
                             var e = autoEntries[idx++];
+                            // Polarized decks (Earthman): polarity-keyed stack
+                            // exists + flashes its FLIP btn per-card. Monodecks
+                            // (Minchiate, RWS): the template renders only `.sea-
+                            // deck-stack--single`, so the polarity-keyed query
+                            // returns null — fall back to the single stack so
+                            // the per-card FLIP-flash UX is the same regardless
+                            // of polarization. User-spec 2026-05-26 PM.
                             var stack = picker.querySelector(
                                 '.sea-deck-stack--' + (e.isLevity ? 'levity' : 'gravity')
-                            );
+                            ) || picker.querySelector('.sea-deck-stack--single');
                             if (stack) _showOk(stack);
                             setTimeout(function () {
                                 // Route thru SeaDeal.register (not the inline