UG: Bell Tapping Code Card
Unique Group offers Bell Tapping Code cards. The knocking codes for communication between the crew of a lost bell and the rescue squad are shown on the bell emergency communications card. This is usually done both on the interior and exterior of the bell.
Composed of knocking codes for communication between crew of lost bell.
Has a rescue squad, shown as a bell emergency communication card.
Comprises interior and exterior bells.
Used between the crew of a lost craft and rescue divers