The world fastest unassisted swim across the English Channel is 6 hours and 58 minutes. The distance is approximately 33km (21 miles). Due to the currents, the actual swimming distance is much longer.
The city of Churchill in Manitoba, Canda, uses helicopters and armed volunteers to surround the city and defend it from Polar bears during Halloween trick or treat night. Noise markers, rubber bullets and even bear traps are used.