Well, Gretchen sorry to do this to you, but here are a couple more conflicting opinions!

I don't know any of the girls that I surf with and travel with (Layne, Megan, Rochelle) that ever think or even have mentioned being afraid to surf while on your period in fear of attracting sharks.

Plus, like Surfline's Alison Sheltrown says, "Well, I take my chances. Because when it's 'Shark Week' (which is what we call it in my house), exercise (and particularly surfing, because it engages the stomach muscles) helps ease cramps. Not to mention, when you feel fat, crampy and otherwise horrible -- getting in the water makes you feel normal again."

I also figured I should ask a shark expert; here's what Ralph S. Collier from the Shark Research Committee has to say:

The question posed by Gretchen is one that is frequently asked of me and is justified by the tragic events at Avila Beach last fall.

There is no scientific data that confirms human blood to be an attractant to sharks. A number of years ago, friend and colleague H. David Baldrigde, conducted a number of experiments using human body fluids to determine whether they were potentially provocative to sharks. One of the fluids tested was human blood. The results in these specific tests showed that human blood did not attract sharks.

However, there are other fluids that are also associated with humans and female menstrual cycles. Without any positive determination sometimes "it is better to be safe than sorrow." My personal suggestions have always been to avoid water contact during that time of the month when a woman is menstruating, even though there is no scientific evidence to support this suggestion.

I understand Gretchen's comment: "It seems there are always good waves that time of the month." The weather always seemed better on those days when I couldn't go freshwater fishing years ago than the days that I did go. Maybe this is because we can't or don't want to do something that makes it seem all the more appealing.