Interesting stuff!...
Throw in High winds-Wave's-Spay,Tide-Stress...like trying to rescue/save Loved one's/children, keeping together,along with low light- miles from shore possible injuries-Panic and Hypothermia ...suddenly those Quality Dry suits along the PLB's, Hand-helds- Personal Flares-(Piro or Laser) Strobes ect seem very Cheap!!
Definitely food foe thought.
Best Saftey??? IMO...Choose you crew and Fellow Boaters well..Two boats + gives you a good Head Start if the the Shit hits.
__________________
A clever Man learns by his mistakes..
A Wise Man learns by other people's!
The Road to HELL ..is Paved with "Good inventions!"
Radar reflectors, look for tri lens passive type or active types, search on ribnet for a review document about radar reflectors because some arnt worth the money at all.
Also get a hand held VHF that floats.
And a PLB - reasonable cost these days and valuable if you have an incident and all power is lost. (goes in your pocket)
anchor with plenty of reope and chain
lifejackets - with a crutch strap and harness
safety knife (goes in your pocket)
first aid kit basic
assorted tools, spare fuses
fire extinquisher
tube pump, tube repair thingy in case of emergency, the type you push through a tear, turn and secure, works well ask PeterM.
spare kill cord
throwing rope
I like BoristheBold's list above...a lot.
I would add a tow rope, or the ability to use your anchor warp as a tow rope
and I would add a Gecko to your personal kit. Even without rain, just putting it on can cut down the fatigue from wind battering considerably. If you have the space to keep one on your boat, I would get one.
You dont have to go crazy on new stuff. Used but good condition Gecko's come up for sale here and ebay frequently.
Imogen
so B.S. is out 
