Jeremy wrote:

Motorcyclist Magazine had an interesting article on the subject recently.
http://www.motorcyclistonline.com/ge...helmet_review/
While the helmets they examined are not suitable for whitewater, some
of the same observations probably apply.

Good article and I agree that their observations probably apply.

There is no official standard for whitewater helmets. The most commonly used
standard is CE 1385. That's a general purpose helmet standard discussed briefly
he http://kayakwiki.org/index.php/Helmet.

Mike