There are also 618 continental islands, which were once part of the mainland. If you see a shark while visiting the reef, consider yourself very lucky as sharks are not frequently encountered by visitors. Of those which are seen the most commonly encountered are the white tip reef and black tip reef sharks. Easily identified by the white markings on the tips of the dorsal fins, they are often found resting upon the sea floor. Like most sharks white tip's are extremely timid and won't stay long around divers.
Most sharks found on the reef are fish eaters and therefore pose no threat to visitors.
Do not harass or block off a shark's exit as they may attack out of fear. Visitors wishing to swim during this period should only do so in protective swimming enclosures or wear protective clothing. The box jellyfish is a coastal species and is not found out on the reef, but they can sometimes be found around islands close to the mainland. Other stingers that are sometimes encountered on the reef include the irukandji and blue bottle. Both can cause a nasty sting, Vinegar can used on both box jellyfish and irukandji stings but not on blue bottle stings.