Oahu is the Hawaiian island with the biggest population, but is only the third in size. The state capital, Honolulu, is on the island, and the legendary Waikiki beach. It has 200 miles of coastline, bathed by the Pacific Ocean. It is the most highly populated island (almost one million people), the most visited and the most urbanised.

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Although the snorkeling spots of Oahu cannot equal those on Big Island or Maui, you can still make some fine explorations on the north (only in summer) and east coasts. You should not expect spectacular coral reefs, since they are now relatively deteriorated. The waters have quite a lot of fish, and in the water it is not unusual to come across green sea turtles, one of the symbols of the Hawaiian marine environment. 450 species of fish and 70 species of coral populate the Hawaiian reefs, including a quarter that are native to the archipelago.

Snorkeling Report Oahu
Frangipani flower, surfer, and fourspot butterflyfish at Hanauma Bay

Most of the snorkeling spots in Oahu are in small coves such as Kuilima Cove or Sharks Cove. They are particularly recommended for beginners when the sea is calm. Hanauma Bay, a superb lagoon with turquoise waters rippling in a dormant crater, claims the title of the most visited snorkeling spot in the world. With an average of 3000 visitors a day (1 million a year), you mustn’t expect to find yourself alone in the water!
When to go to Oahu?

There are two main seasons in Hawaii. The summer, from May to October, is the warmest, driest and sunniest season (with an average of 80°F/26.5°C, and maximum temperatures of 85°F/29.5°C). This is the hurricane season, but they are rare in the North Pacific. In winter, from November to April, the weather is wetter and more changeable (intermittent tropical rains and sunny spells), and the air is cooler (an average of 75°F/24°C, with maximum temperatures of 78°F/25.5°C). As so often in tropical islands, the climate is different on the windward side, more humid and windy (the east) and the leeward side, dryer and more sheltered (the west).

The water temperature can fall to 73°F/23°C in winter (which is still a good temperature for snorkeling), and reach a peak of 84°F/29°C at the heart of the summer (June to September). Lastly, you should remember that winter is the surfing season in Hawaii, and the northern coast of Oahu (the famous North Shore, internationally known for its record-breaking waves) becomes hard for snorkelers to access.


Where to spot them?

Green sea turtle

Take your chance at Hanauma Bay or Turtle Bay

Yellow tang

On all spots

Achilles tang

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Threadfin butterflyfish

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Bluestripe butterflyfish

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Reef triggerfish

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Saddle wrasse

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Moorish idol

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Fantail filefish

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Bluefin trevally

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