The little bombs are called float flares. They are mostly made of wood so they will float in water. They have a heavy metal nose usually made from cast pot metal so they will float nose down. The flare flame emitted from the back of the little bomb from inside the box type sheet metal fin assy.
The idea was to drop them over water, or ground too I would imagine, at night for navigational purposes. The navigator would sight on them to obtain wind drift information with the drift meter. I guess ocean current wasn't much of a consideration for this. At night you didn’t have a reference object to sight on to take a drift reading so they brought along their own spotting devices; float flares.
I believe that if you flew three legs of a triangle and took a drift reading on each leg you could also come up with an average wind direction and velocity by the plot on your E6B computer.
I also understand that the flares could be used to mark targets like subs for depth bomb runs.
Most all aircraft that carried a navigator in WWII had float flares onboard. All of the flares that I have seen carried typical Navy markings (Mark_Mod type of nomenclature) although the ones used in Army aircraft had the same Navy designations.
I have never talked to a Navigator who actually used them nor have I ever read about their use so any first person stories would be most interesting to hear.
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