Northeast of Hanalei on Kauai, the snorkeling at Hideaways Beach (aka Kenomene Beach) is well known. Some tourists refer to this beach as Pali Ke Kua Beach, but that beach is actually a little further east from Kenomene Beach and can be accessed from Kenemene Beach by climbing over the rocks or snorkeling east around the rocky point.
While snorkeling at the secluded Hideaways Beach, you may encounter green sea turtles, butterflyfish, humuhumunukunukuapua’a (Hawaiian state fish aka rectangular triggerfish), goatfish, moray eels, moorish idos, orange spined tangs and parrotfish among califlower coral heads. The water depth ranges from 5 to 20 foot deep. Since it is shallow, the best snorkeling off Hideaways is about 1 hour before and after high tide. If the water is calm, you can snorkel east around the rocks to the hidden Kenemene beach where the better snorkeling is to the far east point. Also, if the surf is calm at Hideaways, there is good snorkeling to be found further out beyond the shallow reef. Watch out for the strong currents with rapid onset at both ends of the beach. From September through May, the surf off Hideaways Beach is affected by seasonal northwest swells that kickup the large waves and generate strong currents so make sure to exercise caution.
To reach the snorkeling in Kauai by air, fly into the Lihue airport (LIH). There are direct flights from Los Angeles, Denver, San Francisco, Seattle and Honolulu. While most visitors to the island rent a car, it is possible to use the public bus but keep in mind that its small and slow. Plus, most of the main snorkeling beaches are well off the bus route requiring some hiking. If you do rent a car, make sure to leave the inside empty when at the beach to avoid attracting break-ins.
To reach the snorkeling at Hideaways Beach, head west on Kuhio Highway (SR56) through Kapa'a towards Hanalei. At Princeville, turn right heading north on Ka Haku Road into Princeville Resort for 2 miles to the end of the road. The public parking is just prior to the main Princeville Hotel parking lot. There is room for only 8 or so cars, so make sure to arrive very early. Alternately, if you're willing to buy a lunch, you can use the Princeville Resort Hotel valet parking which is complementary with beach bar lunch purchase.
The hike from the cliffside parking area down to the beach is very sketchy. It involves sections of broken, rusted stairs and slick, near vertical, trail. This route down to the beach is not recommended for children, and sturdy hiking boots are recommended. Turn back if you feel uncomfortable. There are two other snorkeling dives nearby at the Princeville Resort Hotel beach and at Queen Emmas Bath.
Before snorkeling at Hideaways Beach, make sure to check the current surf report. The waters off Kauai are known for potentially strong currents, high surf and rogue waves. Luckily, there are excellent up-to-date surf reports that can provide guidance on these adverse conditions. WIth the usually rolling surf, it is strongly discouraged to use open-tube snorkels which are common at snorkel rental locations -- only use snorkels with a dry-top splash-guard and a sump purge-valve in the mouth piece. In addition to changing surf conditions, a Hideaways Beach snorkeling dive may expose you to sharp coral reefs and you may encounter sharks, such as whitetip reef sharks, galapagos sharks and tiger sharks. Most snorkeling shark attacks in Hawaiian waters tend to occur near spear-fishing snorkelers, so be aware of the activities of others in the water.
Overall, Hideaways Beach is the 8th most popular snorkel dive spot of all 23 snorkeling dives in Kauai.