Surfing Alone: How Much More Dangerous

I'm lucky that there are fewer surfers around here (north of Eureka, CA). But it often means I am surfing alone. It's great to have every wave to myself, but I worry a bit about the added danger.
Is it really that much more dangerous? Have you personally had an accident or shark attack in which having someone else around was critical in your survival or at least lessened the impact of your problem?
Thanks,
Al
Is it really that much more dangerous? Have you personally had an accident or shark attack in which having someone else around was critical in your survival or at least lessened the impact of your problem?
Thanks,
Al