IMHO having more than one item that you need to get out of the aircraft is asking for trouble. Any survival equipment you need on/in water should be in the dinghy or attached to your person. I have the ELT attached to me/pax and the dinghy on the back seat. If there is a passenger he hugs the dinghy on the way down.
If there is a grab bag perhaps this contains items that would be nice to have but are less essential at sea.