This beautiful and pristine reef is very close to the main shipping channel entering Apra Harbor (but it's not in the channel area) and can be hard to find. It's located about 100 years north of the ammo wharf on Orote Point.
This domed shaped reef is about 100 yards long and 20-30 yards wide that has a southeast to northeast orientation. The entire top and sides of this reef are covered with many varieties of corals and sponges. Hidden reef has some of the healthiest coral growth on Guam.
On the northern side at about 100ft there's a strange metal structure, probably from ww2, with a large wheel or control valve wheel on it.
In one area there are five anemones, complete with resident clownfish. There are many schooling rainbow runners and damselfish moving across the upper regions in large numbers. This is a very good NITROX dive.