The world inside the sea is different; dark yet colorful; calm yet wild and known yet unknown. It is really difficult to let go of such a world without seeing. I didn’t miss the chance of a submarine tour when I was visiting Hawaii. I can’t emphasize enough that it is one of the must-do activities in this exotic island. I purchased a ticket from Atlantis in Waikiki and spent a memorable afternoon 100 ft under the surface of the Pacific ocean.