Symbolic meaning (from the original description):

1 - 8 	The lifeboat is launched.  
9 - 16	Rescue equipment ..  
17 - 24	The wheel.  
25 - 30	Over the waves to the boat in distress.  
31 - 32	The knot between the two boats is tied.  
33 - 40	Back to safety towing the rescued boat.