If you are a kayak wave surfer or white water river runner a helmet is a must. These water sport helmets can be used for all paddling disciplines that can involve risk, such as white water rafting, river boogie, rock gardens and sea caves. Rock hazards on rapid rivers are an obvious threat. One may think that kayak surfing ocean waves on a sandy beach does not pose a threat, but collision with your own kayak is highly probable, and many surf kayaks have sharp fins. No, your bike helmet or skateboard helmet will not do. Nor is a kayak helmet appropriate for skiing or snow boarding. A water sports helmet has the proper lining and fittings for immersion, and should be only used for water sports. See the related article on Helmet use.