On 12/03/2013 20:35, SteveW wrote:

I would think that many lifeboat launches are rescue missions to a
"known" location, navigation systems being so good these days. If it's
going to be a full search, a helicopter or plane is going to cover a
much larger area and much faster.

SteveW


If a man falls overboard you *might* know the position to a few hundred
metres, its still going to be hard to find them in the dark.