The northernmost edge of this beach is a flat rock/coral slope, rather like a boat-loading ramp. It's a cut in an otherwise uninterrupted coral wall, so naturally it will have a strong outgoing rip current when waves are high. Follow the right wall outward. It will lead to gradually increasing depths, until finally you reach a massive tower beside an equally impressive 90' sea cliff that starts at 15' below the surface and goes down from there. Beside the tower is a 60' long deep "notch" or "valley" or "crack" that is as deep as the sea-cliff itself. Corals, morays, and a scattering of fishes make this site nice. It's not nearly as impressive or dramatic as other beach dives on Saipan, but offers a nice alternative if you just want to be utterly alone in crystal-clear water. Bring gloves, because you will have to stick your fingers into sharp holes to clamber back the last 60' shoreward against the rip-current.
Head North. You'll pass the Nikko Hotel on the left, and then on the left, you'll see a dirt road (tough on a rent-a-car). Follow this dirt road to its northernmost extremity. You'll see that you're paralleling a loooong empty white pebble beach. This is Wing Beach. You're only interested in the Northernmost end, where there's a small empty field to park, adjacent to the beach. Gear up at your car, and walk down to the water. THERE ARE NO FACILITIES OF ANY KIND HERE. No bathroom, no other people, no phone, no water, no electricity.