i live in vienna, i see boars regularly in the viennese forest. you just walk past them, stay calm, no problem. if there are piglets you stop and observe, never get between the piglets and their mother.
i can say with certainty that i would react quite differently if i saw a shark while swimming in the sea. but of course, pissing myself in the sea is no big embarrassment.
I've seen a shark while swimming in the ocean before. No big deal. I believe it was a reef shark (in hawaii). Under 6 feet (2 meters) long, a decent distance away, never showed the slightest bit of interest in me (or the other people I was swimming with), and I left it alone. I was more worried about staying away from the pufferfish.
We just don't look like food to most sharks. If visibility is good and there isn't the smell of food in the water, there's usually nothing to worry about.
In Oregon, the local department of fish and wildlife has declared "feral pigs" a nuisance, meaning they can be hunted as much as wanted. They rip of farms, destroy fences etc. Every once in a while, they eviscerate someone, which keeps it interesting :)
i can say with certainty that i would react quite differently if i saw a shark while swimming in the sea. but of course, pissing myself in the sea is no big embarrassment.