There aren't any beaches in Charlottetown, but this is for the people who want to go up to the beaches on the north shore of the island. Most of the beaches have lifeguards, but you must still be careful. If there is an undertow, DO NOT go out too far and if you do get caught in it, don't try to fight against it. Even if you're an olympic swimmer, you won't be able to fight against it. Just swim parallel to the shore until you can get out of it. Also, watch out for jellyfish. They won't kill you, but getting stung is not pleasant. Be careful of crabs in certain places too. Also, pets are not allowed on the beaches in the national park. The private beaches are not supervised, and it can be dangerous to go swimming at night (I've heard about sharks in the water).
Don't swim in the Hillsborough river, the water is not clean enough for swimming.
If you go to Victoria Park, DO NOT swim in Deadman's Pond! I can't stress that enough. The water is totally polluted and contaminated, and there's often broken glass and junk like that at the bottom. Well, if there is a bottom - I've heard from several sources that it is bottomless and haunted...
Do not walk around alone late at night. This is a small province so a lot of people think that bad things don't happen here, but they can and they have. Beatings, murders, etc have happened in little old Charlottetown.
NEVER EVER go to Victoria Park after it gets dark. There are weirdos there who are just looking for trouble, especially in the woods.
Drink druggings (aka the date rape drug) have happened here too, so if you're in a bar, never leave your drink unattended and never accept a drink from someone else who brings it to you.