If you are planning on stopping at Green Sands beach, bring plenty of water, sunscreen, hiking shoes and leave your afternoon open.The hike to Mahana Bay is 4 miles round trip. The drive to Mahana Bay,  requires more than even 4WD. A few local companies drive people in and out for a small fee. If you're a beginner snorkeler, only attempt to snorkel Mahana Bay when conditions are calm. Big south swells, common in summer months, cause strong and dangerous currents.

Mahana bay offers no amenities, other than a sandy beach and spectacular views. There are no concessions, so brings a lot of water, especially for the hike.

From Kona, head south on Highway 11, and turnoff at Ka Lae on the right side of the highway. As you come closer to the ocean, look for a Y and turn left here, heading towards Kaulana Bay. From the boat ramp at the end of the road, head to the left, or east, for two miles to Mahana Bay. After about 15 minutes of walking, the side rim of Puu Mahana cinder cone comes into view.