Hawaii
The Big Island of Hawaii is as the name implies, the largest of the major Hawaiian Islands. It is so large in fact that you could take the land area from all the other Hawaiian Islands combined and fit it within the boundaries of the Big Island. Being such a large island you might think that it would have a large population but actually it has one of the smallest "resident to land mass" ratios in the state.
The Big Island is the only island in the state that actually still has active volcanoes and these volcanoes are quite active on a continuous basis and provide for some thrilling sightseeing. The place to visit to see these volcanoes on Hawaii is the Hawaii Volcanoes National Park on the Hilo side of the Big Island.
The opposite side of the island or leeward coast is referred to as the Kona side of the island and is quite warm and sunny in contradistinctions to the wetter spots on the windward Hilo side of the island. The Kona Coast of the Big Island has the distinction of being one of the most famous sport fishing locations on the planet and is particularly famous for the enormous Pacific Blue Marlin that are hunted here.
The Big Island has so many beautiful and spectacular landscapes and they are often great distances from one another. To really see the island well it would be advisable to spend a few days on the Kona Coast and some time on the Hilo side as well.
Maui
The county of Maui actually consists of a cluster of islands: Maui, Molokai, Lanai, Kahoolawe and the tiny inlet island of Molokini. These islands are all located on the same underwater mountain which comes from deep below the ocean surface. The areas between these islands are shallow channels that have been carved by nature over time. If you were to draw a circle around the entire island cluster that adhered to the outer coastlines of each island the area immediately outside that circle would be deep water in most cases descending sharply with steep drop-offs to the bottom of the ocean. By contrast, the channels between the islands would be very shallow, in many places no deeper than three-hundred feet.
The biggest island, Maui, is the most popular and consists of two huge mountains: Mount Haleakala which rises 10,000’ above the ocean surface, and the West Maui Mountains which rises about half that high. These islands are separated by a large valley from which Maui gets its nickname "the Valley Island”. For an island that only extends about forty-eight miles from end to end there are as many climatic zone here as exist on the entire coastline between Alaska all the way to Costa Rica. This provides a rich environment for the many types of activities that are available on the island of Maui. In fact, the island of Maui, with its sister islands, provides more tours and activities and more categories of activities than are found on any other island in Hawaii and most likely, more than any other location on earth.
Oahu
Oahu Island serves as the capitol of the Hawaiian Islands and the seat of power for all Hawaii lies in the major city of Honolulu. Oahu itself is only the third largest island in Hawaii in terms of land area but has a greater population by far than all of the other Hawaiian Islands combined. This is an island of major population centers but also of beautiful country regions.
The major reason for Oahu's position of importance over the years has been a result of its huge ocean port of Pearl Harbor. From its early times Pearl Harbor has provided a welcome protection from the ocean waters surrounding the island and certainly has become the most important point of ocean commerce in the state of Hawaii.
Of all the Hawaiian Islands Oahu is the one that has the largest presence of theaters and shows and also has the very largest visitor attractions in the state. Though the island is populous it also has beautiful coastlines and remote areas and is home to some of the most unique snorkeling and dolphin watching coastlines in the state.
Kauai
Kauai is the very oldest of the major islands of Hawaii and its volcanoes have been extinct for well over five-million years. It is the most northern island in the Hawaiian chain and from its shores the ocean extends uninterrupted for two thousand miles to the north, west and south before reaching any other land mass. This isolated location of Kauai makes it the very first landfall for any weather conditions generated from the North and West Pacific and as a result has very high rainfall totals and consistent winds and waves that hit its coastline. In fact the island of Kauai is actually the wettest place on earth with its highest mountain of Wai aleale receiving an average rainfall of about 420' a year.
Kauai's location in the Pacific has created a couple of unique geological oddities which none of the other Hawaiian Islands can claim. The first is the Napali Coast. This is an eleven mile coastline that because of the severe rain, wind and ocean impact on its shore have created a magnificent coastline of sheer emerald green cliffs descending thousands of feet from the island center to the remote white sand beaches and ocean caves at the sea level below. This cliff-line is also adorned with some of the largest and most beautiful waterfalls to be found anywhere in the world. The Napali Coast provides a great location for all types of tours and activities including boat, kayak and rafting trips, snorkeling tours, helicopter and airplane tours and sunset and dinner cruises.
The second great geological distinction that Kauai has from the other islands in the chain is the huge alluvial plain that has been created on the eastern areas of the island which is also a direct result of its extreme rainfall. This fairly flat surface on an otherwise mountainous island has been created by the enormous erosion caused by rainfall from its mountain summit depositing soil on the eastern boundary dissected by multiple rivers. Kauai in fact is the only island in the Hawaiian chain that has navigable rivers at all and as a result provides fantastic access to the sports of kayaking, canoeing and other water sports on these rivers which are unavailable on any other Hawaiian Island.