This is a common misconception and you should know that scuba tanks are never filled with pure oxygen. This is because, ironically, this gas that gives people life is lethal when breathed under pressure. This can cause oxygen toxicity and can cause instant death. Scuba tanks are often filled with air, similar to what we breathe on the surface, that are compressed to about 250 bar or 3000 pounds per square inch. Truly, it can be relaxing on your part as you will be able to watch different sea creatures roaming the vast water. Seeing the beauty below the sea is a great thing to have unless you will be assisted by professionals that knows the waters that can help you in any case of emergency. Precisely, before taking any scuba diving experience, you should have the all the necessary scuba diving equipment. Today, there are quite a number of scuba diving agencies that certifies scuba divers, such as PADI, NAUI and SSI that teaches and trains people to go scuba diving. If you want to go scuba diving, you first need a certification in order to go scuba diving. Scuba diving resorts will never allow you to go diving without certification from any of the agencies mentioned. The tunnel caverns, arches and lava tubes are excellent venues for picture taking or setting a night dive with Manta Rays or a blue water dive to search for the spotted and bottlenose dolphins, pygmy killer whales, pilot whales and whale sharks. It is recommended to take a guide if you are planning to dive in Hilo side of the island. Grand Cayman has a lot of dive sites with different certification requirements. This means that you have a lot of choices on where to dive but a particular dive site will require a minimum certification level to ensure your safety. For example, if you are certified as an open water diver, you are only allowed to dive in dive sites that have a minimum requirement of open water diver. Giving concern to the environment is just caring for your fellowmen. Every person should realize this reality. The world is indeed in chaos not only because of war and misunderstanding between races but because of the environmental destructions. Scuba diving in Hawaii is an important activity for the people.