Starting in south from Ulehawa Beach and heading north up to Pokai Beach, these are the beaches in the middle of Oahu's Leeward Side. Read this "Star-Bulletin" article about beach safety in Hawaii.
Ulehawa Beach County Park
Leeward Oahu, Hawaii. The relatively-underdeveloped beach at Ulehawa offers good bodysurfing conditions as well as good, generally safe year-long swimming in the shallow lagoon. Also, some spots along the beach are known to be especially accomodating to the casual line-caster.
Location :: Just north of Nanakuli, along Farrington Highway.
Access :: Farrington Highway.
Services :: Picnic facilities, restrooms, lifeguards, camping allowed (with permit).
Maili Beach County Park
Leeward Oahu, Hawaii. Nestled between two mountain streams running out to the ocean, the encroachment of a housing development has split the beach at Maili into three sections. Though most of the beach is suitable for swimming, the portion in front of the lifeguard tower is best for it. Scattered pockets of coral offer good snorkeling.
Location :: Southern end of the town of Maili, along Farrington Highway.
Access :: Farrington Highway.
Services :: Picnic accomodations, restrooms, lifeguard tower.
Notes :: The beach is swallowed up by the winter tides, but reappears come the summer. Though the waters here are reasonably safe, they are known to be dangerous on occasion, and it's best to check with the locals or the lifeguard before taking the plunge.
Lualualei Beach County Park
Leeward Oahu, Hawaii. This undeveloped beach rests along low cliffs. Rough waters make for nigh-impossible swimming. The beach is better utilized for its beautiful views and decent fishing.
Location :: Waianae, along Farrington Highway.
Access :: Farrington Highway.
Services :: Picnic facilities, restrooms, camping (during the summer months).
Pokai Beach County Park
Leeward Oahu, Hawaii. The most-developed, as well as most visited beach on the leeward coast, Pokai's sands are spotless, its waters safe for swimming year-round. Pokai also offers good surfing and snorkeling conditions.
Location :: Waianae, along Farrington Highway.
Access :: Farrington Highway.
Services :: Picnic facilities, restrooms, lifeguards, boat ramp.
Notes :: A replica of a Polynesian double-hulled canoe is often docked at the boat ramp. It is used primarily for publicity purposes, and may even seem vaguely familiar as it has appeared in a TV beer commercial.