Monolith

Monolith is a large offshore volcanic pinnacle with a flat top around 40 ft and a base extending to roughly 90–110 ft. The pinnacle and adjacent ridge feature steep lava ledges, coral gardens, and large black coral colonies that form a dramatic open-water structure. Notable marine attractions include longnose hawkfish, schools of orange Hawaiian longfin anthias, occasional large pelagics and spotted eagle rays, and a resident yellowmargin moray eel known to approach divers and serve as a photographer's highlight. Access is by boat only. Conditions are very clear with excellent visibility, and currents are often strong enough to create a drift profile. Depths range from about 40 ft at the top down to 90–110 ft at the base, so dives are planned on computers or tables to remain within no-decompression limits; the site is generally recommended for advanced-level divers. Water temperatures are generally warm, in the 70s °F. Main hazards are depth and strong currents, so good buoyancy control, ascent planning, standard safety stops, air management for a deep dive, remaining close to the group, and a powered ascent when finishing are advised.