Located about 5 miles south of Kailua-Kona on Ali'i Drive, Kahalu'u Beach Park is a great option for some quick snorkeling close to town and a good destination for some family beach time. The beach is located in a shallow bay, and the ocean floor here consists of reef and lava rock. While there may be better beaches in and around Kailua-Kona for swimming (such as La'aloa Bay and Kona Beach), the underwater habitat here is robust and worth bringing your snorkeling gear to explore (or you can rent gear on site). The sand is a little coarse, but that doesn't stop plenty of folks from laying out for the day or enjoying a picnic at the tables. Surfers can also find a break near the northern end of the bay just offshore from the endearing St. Peter's Catholic Church.
Amenities include showers, restrooms, gear rentals, a snack shack, picnic tables, and the watchful eyes of lifeguards. This beach does get crowded, of course, and there is limited beach space, so mornings are best if you are arriving with a larger party.