Crinoids and gooseneck barnacles on a dead sponge, over 5000 ft. off Hawaii. Antedon (crinoid)

Gold coral on pillow lava in over 1000 ft. off Hawaii. Gerardia

Satin sponge on basalt slope, at 5000 ft. deep off Hawaii. Semperella

Isolated tufted corals are common on the deep rocky slope off Hawaii.

Glass sponge between red crinoid stalk and gorgonian on pillow lava off Hawaii. Walteria (sponge), Chrysogorgia (gorgonian)

Blackbellied rosefish and rock crab in 1000 ft. off New Jersey. Helicolenus (fish), Cancer (crab)

Pillow lava rocks on the slope off Hawaii form when magma oozes from below.

Yellow iron oxide comes from hydrothermal vents; white is bacterial mat.

Yellow iron oxide covered lava rock on the flank of Loihi submarine volcano.

Ancient coral reef below 700 meters of water off Hawaii.

Cemented ash and talus at a depth of 755 m off Hawaii.

Inactive hydrothermal chimneys made of iron oxide on Loihi volcano.

Duckbill eel in a sand channel between basalt flows at 780 m depth. Nettastoma

Sponges and crab on a basalt talus slope.

Sub manipulator sampling basalt rocks on the flanks of Loihi volcano.

Trays containing rock slabs deployed on ferro-manganese crust at Cross Seamount.

Pillow lavas

Scuba divers change out a current meter used to monitor currents in the Bahamas.

Stereo photography allows diver scientists to measure the size of corals.

The Perry Cubmarine wet sub carries two divers at speeds of up to 5 knots.

Diver checks the performance of a fish trap used to collect reef fish.

Some sponges have symbiotic algae and can bleach like corals.

Divers training in handling a disabled dry suit diver.

Divers studying conch biology in the Bahamas.

Preparing to drill into a coral reef to study climate over the past 20,000 yrs.

Underwater gear is maintained by divers to clear fouling and retrieve data.

Aquanaut uses a buoy to signal the surface and raise equipment.

Snorkeler retrieves ghost traps from the grip of a submersible.

Ice diving in the Arctic requires special equipment and a smart dive plan.

Diver riding a shrimp net watches a turtle escape through the excluder device.

Elkhorn and staghorn corals provide beauty and complexity to the reef.

Divers collect shallow sediment cores to track coastal erosion processes.

Close-up underwater photography of coral reefs can only be done by divers.

Divers use a suction sampler to collect animals living in the sand.

School of jacks patrol the reef.

Deploying a plankton net in a kelp forest to collect larval fish.

Technical diver, using mixed gases to dive to 60 meters, decompresses.

Diver carries samples to the surface.

Divers use a two person diver propulsion vehicle.

Black durgen removed from its shelter.

Divers adjust micromanipulator used to sample close to coral heads.

Aquanauts change out tanks near the Aquarius undersea laboratory.

Captured reef fish are tagged and released.

Diver conducts point counts of reef fish.

Diver relocates a fish trap used for transplant experiments.

Core sample collection in the muddy sands of Long Island Sound.

Divers transport benthic chamber used to measure productivity and respiration.

Diver prepares to enter a shark cage.

Coring into a coral reef to discover clues to past climate changes.

Diver training with a full face mask and underwater communications.