Back on the topic of harnesses and PFDs:
I would like to put in a pitch for the humble foam type III pfd combined with a traditional webbing harness.
In hot climates, the foam PFDs may not be the best, but many of us sail in less than tropical conditions and I believe they offer the following advantages:
The foam PFD adds a lot of insulation and can easily be layered over, or under follies for added warmth.
The type III can not (realistically) malfunction with its primary purpose. Flotation. No triggering device to corrode, no bladder to puncture.
You can swim effectively in one of these, allowing you to participate in your own rescue.
They can be easily integrated with a traditional webbing harness at little expense. It doesn't take much imagination to figure out how to thread the harness though some of the Type III buckle loops and make your own combo PFD/harness at low cost.
The foam protects your ribs and vital organs from your harness. If you do take a huge fall onto your harness, the foam will help spread the load and prevent you from cracking ribs, or worse. Speaking of which, how well do those "one size fits all" inflatable harnesses fit you? If they're below the ribs you risk a ruptured spleen or lacerated liver.
The foam protects your ribs and vital organs from other falls. Tether falls notwithstanding you can easily fall on a pitching, wet deck and your torso may contact the deckhouse, cockpit seat, or even a winch. Again the foam padding may protect you.
Comfort. Sometimes I end up wedged in some uncomfortable part of the boat, especially when racing. I'm often curled up on my side on the rail, with a piece of deck hardware poking into my ribs, or leaning against stainless lifelines. The foam PFD makes these uncomfortable positions much more bearable.
As cool and space age as the sub $500 Spinlock harnesses look, give the good old type III and webbing harness a second look.
PS One makes an excellent point about wearing a helmet. Many sailors talk about (and spend extra money and maintenance time) trying to mitigate for the possibility of going overboard unconscious. Automatic inflation is the wrong approach, as I have outlined before.
Obviously not going overboard first is the most important step (tether) but since it may happen, instead of spending the money so that the unconscious (and likely drowned) victim floats, why not spend the money and effort on a helmet, so that he's not unconscious in the first place? If we really do fear this scenario (I don't), it seems like a much better mitigation strategy.
A dock-mate of mine (a neurosurgeon I believe)used to race his J-boat single handed. He always wore a helmet. The America's Cup cat racers are also wearing helmets now too.