Underwater Guide to Hawaii

Clown fish under water with diver
Hawaii Aloha Travel > Blog > Underwater Guide to Hawaii

Everyone writes the ultimate guides for Hawaii’s land characteristics, like the ultimate guide to Hawaii’s waterfalls, beaches, hiking trails, etc. But what you rarely find is a guide to the underwater world of these tropical islands, which is just as diverse and exciting as the above-the-surface stuff. Plus, snorkeling, diving and swimming are major activities for anyone visiting these islands, and I find it just as important to know the ins and outs of the ocean as you would the land. Even if you don’t plan to snorkel, you can at least familiarize yourself with the underwater fauna and get an education on the bounty and beauty of Hawaii’s marine life.

I’ve created a list of creatures you’re sure to see during your vacation here in Hawaii, starting with the immobile marine life like coral, seaweed and sea urchin, then move on to the fish, then sand dwellers, and lastly the bigger creatures of the sea. Be sure to use this guide when you sightsee the underwater world of Hawaii’s great Pacific Ocean!

Much of the reef you’ll see in Hawaii might simply look like rock. But don’t be fooled.
Hawaiian coral reefs account for about 85 percent of all coral reefs in the US, and are very much alive. The reefs here are a combination of living coral, dead coral and soft coral and are a habitat to many creatures such as fish, lobster and octopus.

Hawaii also is rich in underwater plant life, such as limu (green seaweed), brown and red seaweed, sea lettuce (a turtle’s favorite food), algae and more. You can also easily spot wana otherwise known as sea urchin, tucked in the cracks and crevices of the reef. Unfortunately, it is quite common for folks to step on these critters, so I either recommend water shoes or entering and exiting the water only from sandy areas. Sea cucumbers are another ‘formation’ you’ll see underwater, and these blobs actually move. By using their tiny tube feet, sea cucumbers can slowly get around the ocean floor or slug over rocks and reef. You can find them almost anywhere in Hawaii’s waters.

The tropical fish are incredibly abundant here, and with no shortage of color either. Neons, patterns, stripes and solids tint the blue water and create a myriad of vibrant color. Common fish to spot are the butterfly fish, which have a variety of different names. You can easily spot threadfin butterfly, longnose butterfly and raccoon butterfly, by their triangular shaped bodies, yellow coloring, long noses and unique coloring.

The humu (shortened for humuhumunukunukuapua‘a) is the Aloha state fish and can be identified by its pig-like nose and bullet shaped body. This reef trigger fish is typically colored in yellows, whites, blacks and blues and squeals when in danger or cornered. But don’t give it a run for its money, the fin on the top of the humu’s body is sharp and can easily cut flesh.

The stick fish is a long-bodied silvery fish that likes to swim in schools and hovers close to the surface. They sway side to side in order to propel through the water, and can get up to three feet in length, however you’ll typically only see them in the one-foot range.

Surgeonfish are most common in Hawaii’s waters, but with over 80 species worldwide and 25 of them living in Hawaii, it’s hard to determine which ones are surgeons. The most popular one is called manini or convict tang, because of its black jail cell stripped patterning. Yellow and black, manini are often caught and cooked by the locals, and taste best when fried. Other surgeonfish species include the blue surgeonfish (or ‘Dorey’ from ‘Finding Nemo’), unicornfish, which have a unicorn-like horn and are typically gray and yellow in color, and yellow surgeonfish which are very common and brightly colored yellow.

A couple other fun fish are parrotfish, which pretty much look like Hawaii in a fish, colored with purples, turquoises and greens, malolo, otherwise known as flying fish, which you’ll likely see jumping out of the water and skittering across the surface, clown fish (otherwise known as ‘Nemo’) and angelfish. Manta ray, which are a flattened fish, are also common to see in the deeper snorkeling territories and are gorgeous and graceful.

On the shoreline, crabs run around in the sand throughout all hours of the day. The most common are the ghost crabs, which burrow in the sand and are a light whitish-yellow color. You can also find ama crabs, which are black and blend in to the volcanic rocks along the water.

Turtles in Hawaii are very common, yet these creatures are becoming increasingly rare. There are two types that cruise the Pacific waters of these islands, the green sea turtle and the hawksbill turtle. The Hawaiian green sea turtle is the most common and feast on the limu that grows close to the shorelines. Hawksbill turtles are rarer and can measure up to three feet long and weigh up to 200 pounds. Critically endangered, hawksbill turtles spend much of their time in shallow lagoons and near coral reefs.

Dolphins are a huge attraction in Hawaii, and you can spot bottlenose, spinners and spotted dolphins easily from the beach or boat. Bottlenose dolphins have a mouth and nose that look like they’re permanently smiling, and are highly intelligent. The most popular dolphins in captivity, bottlenose dolphins can be trained to performed complex tricks.

Spinner dolphins get their name from the pirouettes they do in the air and are smaller than bottlenose. Their acrobatic displays are popular forms of entertainment for guests on catamarans and sailboats, and are often found in popular swimming areas with deeper waters. Spotted dolphins are easy to distinguish from the other two species because of their white spots. They are slender and small, and the rarest of all dolphins in Hawaii.

Humpback whales migrate to Hawaii yearly, and are the largest creatures that pass through Hawaiian waters. Traveling north from Alaska to the warmer seas of Hawaii, humpback whales journey to the islands to mate and give birth. From December through May, whales can be spotted off the coast of all Hawaiian Islands, just keep an eye to the horizon and you’re guaranteed to see spouts or breaching.

Now that you’ve got the rundown on Hawaii’s marine life, it’s time to get out there and do some exploring! Enjoy the warm ocean and the colorful creatures, and don’t forget to malama ke kai, care for the ocean.

No tags