Hey folks, just sharing my personal experience.
Ultimately, each of us will make the decision they feel comfortable with.
At least helmets are available!
Duzzi, you missed the following sentence

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duzzi said..Manuel7 said..
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Similarly I hit my sail with the side of my head wearing a helmet at much lower speeds than above and felt like the impact was much greater. I feel like the helmet padding needs to be quite soft as the increased head area makes it harder to break water surface tension.
I used a helmet before and had to take it out because of repetitive hits on the water from throwing moves, my head would hurt during and following the sessions due to the increase surface of the helmet. Maybe it was the helmet, just sharing my thoughts.
Also, yes it'll put strain on your neck because the added weight, when you slap on your back your head goes back and hits the water. You will hear your back and neck crack actually, sometimes it feels good
The most important thing is don't let go and certainly never the front hand until you are clear of trouble.By keeping the front hand on it'll be impossible for you to hit the mast. If you can't hold it then you'll be ejected far enough from your gear anyway.
I do recommend ear protection 100%, sun protection, rashguard, rib or torso padding, and maybe a lightweight thinner helmet if you feel like it.
In regards to whip lash, look at the Hans device, it's mandatory for some racing. Luckily for us, our sport has much better numbers in terms of injuries than driving to and from our local spot!