West of Honolulu on Oahu, the snorkeling at Kahe Point Beach Park (aka Electric Beach) is known for its abundant marine life. Due to the nearby electric plants, the water is a little warmer here attracting more fish. The marine life includes parrot fish, butterfly fish, wrasse, tang, snapper, triggerfish, squirrelfish, unicorn fish, jacks and needle fish. Also, this are is popular with spinner dolphins. The best place to enter the water is just to the north side of the large pavilion.
The Kahe Point Beach Park is recommended for intermediate to advanced snorkelers due to the distance of 500 feet to the good diving near the pipe outflows. The water depth at the pipe outflow is about 20 feet.
The best place for snorkeling at Kahe Point Beach Park is off the small beach to the right of the large pavilion. You will need to pass through the breaks to get to the calm water. You may want to only explore here during the calmest surf of the summer months.
To reach the best snorkeling on Oahu by air, you will need to fly into Honolulu International Airport (HNL) which is located just on the west side of Honolulu. There are direct flights into Honolulu from the US, Australia, New Zealand, American Samoa, Tahiti, Japan and Fiji. In addition, there are inter-island flights to all the main Hawaiian Islands. The Kahe Point Beach Park is located about 30 minutes from the airport.
There is good snorkeling on Oahu year-round. But, the conditions very around the island depending upon time of year due to winds and currents. The north shore snorkeling dives are best from June through September and are usually closed out the rest of the year due to high surf. The south shore dive sites are best from November through May. The main exception is Hanauma Bay, which tends to be good year-round since it is very protected.