Which symbol on a regulatory marker is used to warn of a rock or other underwater hazard?

Diamond shaped regulatory marker.

Explanation: The regulatory markers are those symbols that are used in order to guide us about any particular place. It warns about the area, how the situation could be, how dangerous it could be, and what are the things that we are not suppose to do. So these informations must be carefully noticed and obeyed.

In order to warn about a rock or any other underwater health hazardous situation, a diamond-shaped marker is generally used in which the diamond shape is made of orange color and the writings are done in black ink.

from my research i have to the conclusion that decomposers, such as fungi, bacteria and invertebrates, play a critical role in nutrient cycling and without them the earth's ecosystem may not support life as we know it. elements such as carbon, nitrogen and phosphorus exist in limited amounts on earth, although huge amounts of carbon are being released into the atmosphere from underground sources now by humans. it is still extremely important that other nutrients be retained by the process of re-use. decomposers are organisms that are able to chemically break down dead material and make these elements available for use by other organisms. without this breakdown of dead material, dead bodies would pile up. so decomposers also play a role in clean up also. without them, life might not continue as we know it and dead material would overwhelm the earth.    

explanation:

on disadvantage of hydroelectric power is the cost. another disadvantage of using hydroelectric power is finding a water source powerful enough to harvest hydroelectric power.