The Grotto

Saipan's best-known site: a natural tunnel from a high cliff down below sea level that opens to the ocean through three openings between the surface and about 18 m, with a large 'batcave' at 12–15 m and walls, swim-throughs and caves outside. Shore dive reached by 111–112 very steep steps. Operators quote maxima between about 22 m (central cavern) and 30 m. Surge and current can be dangerous and the site is closed by the authorities when the sea is rough.

Facts

• Region: Mariana Islands – Guam & Saipan
• Area: Saipan
• Depth: 0–30 m
• Level: intermediate
• Current: strong
• Type: cave, wall
• Coordinates: 15.268, 145.814 (approximate)
• Highlights: cavern, three exits, white-tip reef sharks, green sea turtles, clown triggerfish, barracuda, humphead wrasse, nudibranchs
• Unverified: No published GPS found; the pin is a map-based placement and is only indicative. (NE coast near the Bird Island lookout)
• Tips: Dive with a local guide; the batcave needs slow air consumption and a guide. Save enough gas to return inside for the safety stop; snorkellers should not exit through the openings in surf. Check for rough-sea closures.

Sources

• https://mva.mymarianas.com/dive-spots/
• https://en.wikivoyage.org/wiki/Diving_in_Saipan
• https://letsgodivingsaipan.com/divesites
• https://www.masadive-saipan.com/eng-point.html