They especially tend to come close to the shore when the winds are calm or off shore. Those conditions are most conducive to their eating/fishing habits. Also large surf stirs up the bottom and brings other predators to the surf area...which are then eaten/hunted by the sharks.
I seen a horseshoe crab yesterday and near crapped me pants!!
Haha. I once had a dream right after that damn sting ray to our beloved steve irwin that I was surfing perfect 8foot barrels. So on my last wave I pulled in super deep and the foam ball clipped me and I got pitched and slammed to the bottom. When I hit the bottom a huge mutated horseshoe crab impaled me with his spike right through the chest haha. I've never looked at one them same since
20 years ago Seals in these waters were utterly unheard of, now there are hundreds of them. I see them all winter long nowadays..on the beach, in the water, in the rivers...so many in fact that taking people on boats to watch them is a viable tourist business (see article)
so, by way of logic, if Seals are here, why would there NOT be large sharks also here, to take advantage of that food source, as well as attack surfers as they have been known to do?