What are the dangerous creatures underwater?

Indonesia
September 11, 2009 9:33am CST
I have been snorkeling for several days now and didn't know what are the dengerous things underwater. I heard that there are numerous of small little things there underwater and very poisonous. I also hear about a reef shark. A friend of mine said that it's very dangerous, also lionfish. Any of you know?
1 response
@Preciousgem (1190)
• Philippines
15 Sep 09
Shark is very dangerous creatures underwater, because if they bit you, your body will cut into pieces, you can live without your part of the body, or die due to your condition.