diff --git a/commands/command_edit.cpp b/commands/command_edit.cpp
index cf2d0e5d3..0617e0e8b 100644
--- a/commands/command_edit.cpp
+++ b/commands/command_edit.cpp
@@ -1052,6 +1052,7 @@ AddCylinder::AddCylinder(bool currentDiveOnly) :
 	else
 		setText(Command::Base::tr("Add cylinder (%n dive(s))", "", dives.size()));
 	cyl = create_new_cylinder(dives[0]);
+	indexes.reserve(dives.size());
 }
 
 AddCylinder::~AddCylinder()
@@ -1066,22 +1067,23 @@ bool AddCylinder::workToBeDone()
 
 void AddCylinder::undo()
 {
-	for (dive *d: dives) {
-		if (d->cylinders.nr <= 0)
-			continue;
-		remove_cylinder(d, d->cylinders.nr - 1);
-		update_cylinder_related_info(d);
-		emit diveListNotifier.cylinderRemoved(d, d->cylinders.nr);
-		invalidate_dive_cache(d); // Ensure that dive is written in git_save()
+	for (size_t i = 0; i < dives.size(); ++i) {
+		remove_cylinder(dives[i], indexes[i]);
+		update_cylinder_related_info(dives[i]);
+		emit diveListNotifier.cylinderRemoved(dives[i], indexes[i]);
+		invalidate_dive_cache(dives[i]); // Ensure that dive is written in git_save()
 	}
 }
 
 void AddCylinder::redo()
 {
+	indexes.clear();
 	for (dive *d: dives) {
-		add_cloned_cylinder(&d->cylinders, cyl);
+		int index = first_hidden_cylinder(d);
+		indexes.push_back(index);
+		add_cylinder(&d->cylinders, index, clone_cylinder(cyl));
 		update_cylinder_related_info(d);
-		emit diveListNotifier.cylinderAdded(d, d->cylinders.nr - 1);
+		emit diveListNotifier.cylinderAdded(d, index);
 		invalidate_dive_cache(d); // Ensure that dive is written in git_save()
 	}
 }
diff --git a/commands/command_edit.h b/commands/command_edit.h
index 257461c59..78c596b6c 100644
--- a/commands/command_edit.h
+++ b/commands/command_edit.h
@@ -386,6 +386,7 @@ public:
 	~AddCylinder();
 private:
 	cylinder_t cyl;
+	std::vector<int> indexes; // An index for each dive in the dives vector.
 	void undo() override;
 	void redo() override;
 	bool workToBeDone() override;
diff --git a/core/equipment.c b/core/equipment.c
index 0fd7644b7..685306981 100644
--- a/core/equipment.c
+++ b/core/equipment.c
@@ -464,6 +464,34 @@ cylinder_t create_new_cylinder(const struct dive *d)
 	return cyl;
 }
 
+static bool show_cylinder(const struct dive *d, int i) 
+{
+	if (is_cylinder_used(d, i))
+		return true;
+
+	const cylinder_t *cyl = &d->cylinders.cylinders[i];
+	if (cyl->start.mbar || cyl->sample_start.mbar ||
+	    cyl->end.mbar || cyl->sample_end.mbar)
+		return true;
+	if (cyl->manually_added)
+		return true;
+
+	/*
+	 * The cylinder has some data, but none of it is very interesting,
+	 * it has no pressures and no gas switches. Do we want to show it?
+	 */
+	return false;
+}
+
+/* The unused cylinders at the end of the cylinder list are hidden. */
+int first_hidden_cylinder(const struct dive *d)
+{
+	int res = d->cylinders.nr;
+	while (res > 0 && !show_cylinder(d, res - 1))
+		--res;
+	return res;
+}
+
 #ifdef DEBUG_CYL
 void dump_cylinders(struct dive *dive, bool verbose)
 {
diff --git a/core/equipment.h b/core/equipment.h
index 8f7cee74a..c82963631 100644
--- a/core/equipment.h
+++ b/core/equipment.h
@@ -94,6 +94,7 @@ extern int gas_volume(const cylinder_t *cyl, pressure_t p); /* Volume in mliter
 extern int find_best_gasmix_match(struct gasmix mix, const struct cylinder_table *cylinders);
 extern void fill_default_cylinder(const struct dive *dive, cylinder_t *cyl); /* dive is needed to fill out MOD, which depends on salinity. */
 extern cylinder_t create_new_cylinder(const struct dive *dive); /* dive is needed to fill out MOD, which depends on salinity. */
+extern int first_hidden_cylinder(const struct dive *d);
 #ifdef DEBUG_CYL
 extern void dump_cylinders(struct dive *dive, bool verbose);
 #endif
diff --git a/qt-models/cylindermodel.cpp b/qt-models/cylindermodel.cpp
index 325f53add..fa0dac1b9 100644
--- a/qt-models/cylindermodel.cpp
+++ b/qt-models/cylindermodel.cpp
@@ -131,27 +131,6 @@ static QVariant percent_string(fraction_t fraction)
 	return QString("%L1%").arg(permille / 10.0, 0, 'f', 1);
 }
 
-bool CylindersModel::cylinderUsed(int i) const
-{
-	if (i < 0 || i >= d->cylinders.nr)
-		return false;
-	if (is_cylinder_used(d, i))
-		return true;
-
-	cylinder_t *cyl = get_cylinder(d, i);
-	if (cyl->start.mbar || cyl->sample_start.mbar ||
-	    cyl->end.mbar || cyl->sample_end.mbar)
-		return true;
-	if (cyl->manually_added)
-		return true;
-
-	/*
-	 * The cylinder has some data, but none of it is very interesting,
-	 * it has no pressures and no gas switches. Do we want to show it?
-	 */
-	return false;
-}
-
 // Calculate the number of displayed cylinders: If hideUnused
 // is set, we don't show unused cylinders at the end of the list.
 int CylindersModel::calcNumRows() const
@@ -160,10 +139,7 @@ int CylindersModel::calcNumRows() const
 		return 0;
 	if (!hideUnused || prefs.display_unused_tanks)
 		return d->cylinders.nr;
-	int res = d->cylinders.nr;
-	while (res > 0 && !cylinderUsed(res - 1))
-		--res;
-	return res;
+	return first_hidden_cylinder(d);
 }
 
 QVariant CylindersModel::data(const QModelIndex &index, int role) const