This subject, as you might have seen, has been hashed about pretty well. My own experience is that seals and sea lions are usually harmless, but they spook the heck out of me. At various times they are thick in our rivers and it's common to have close encounters. My theory is that it would only take one time for one of the big bulls (up to 3000 lbs.) to totally ruin your day. They are wild animals and unpredictable. I don't even like the harbor seals, which have popped up right next to me and scared the crap out of me. I leave them alone and expect the same from them.