Figure 82. - Ventriculites simplex, Toulmin Smith. Section of the outer wall, showing the structure of the silicious network of this sponge. In: Thomson, Wyville. 1873. The Depths of the Sea. MacMillan and Co., London.

Figure 83. - Coelosphaera tubifex, Wyville Thomson. Off the coast of Portugal. A strange sponge. In: Thomson, Wyville. 1873. The Depths of the Sea. MacMillan and Co., London.

Figure 84. - 'Choanites'. In a flint from the white chalk. A fossil tunicate. In: Thomson, Wyville. 1873. The Depths of the Sea. MacMillan and Co., London.

Sounding by hand with a Lucas sounding machine while approaching Antarctica on Scott's ship the Terra Nova. From: Cherry-Garrard, A. 1922. "The Worst Journey in the World."

A remarkable discussion of possible disaster from a ship collision with an iceberg. The description of the danger was made by Captain Charles D. Sigsbee, Chief of the Navy Hydrographic Office, captain of the MAINE two years after this article was published which was 16 years before the TITANIC disaster. He commanded the BLAKE and wrote "Deep Sea Sounding and Dredging."

Baseline measurement over the remains of the Coast and Geodetic Survey Steamer HASSLER.

Baseline measurement over the remains of the engine of the Coast and Geodetic Survey Steamer HASSLER.

Marine archaeologist taking measurements over the engine of the Coast and Geodetic SurveySteamer HASSLER.

Boiler stays and end remains of the Coast and Geodetic Survey Steamer HASSLER.

An iron plate from the HASSLER's bow embedded in the rock pinnacle that sank the ship in 1898.

Remains of forward deck plates of the HASSLER.

Dr. John Jensen of the Sea Education Association of Woods Hole, Massachusetts, and Dave McMahan, Alaska State Archaeologist, preparing to dive on the remains of the HASSLER.

Details of the double hull of the HASSLER.

Baseline measurement over the engine area of the HASSLER.

Baseline measurement over the engine area of the HASSLER.

Plan view of the engine area of the HASSLER.

Baseline measurement over the engine area of the HASSLER.

An iron plate from the HASSLER's bow embedded in the rock pinnacle that sank the ship in 1898.

Tapering of hull space between double bottoms is evident at ship extremities.

Dr. John Jensen launching the Seabotix tethered robotic vehicle used on this mission to study the HASSLER.

Boiler stays of the HASSLER.

An iron plate from the HASSLER's bow embedded in the rock pinnacle mission to study the HASSLER.

Rudder of the HASSLER.

The shaft of the HASSLER.

The shaft of the HASSLER.

A marine archeologist measuring the baseline along the propeller shaft of the . HASSLER.

Looking forward from the starboard quarter of the HASSLER.

Dr. Hans Van Tilburg tending divers working on the HASSLER. Eldred Rock Lighthouse is in the background.

Bitts on the HASSLER.

Boiler face of the HASSLER.

A marine archaeologist taking measurements of the boiler face of the HASSLER.

A marine archaeologist taking measurements of the boiler face of the HASSLER.

A marine archaeologist taking measurements of the boiler face of the HASSLER.

A marine archaeologists sketch of the debris field of the HASSLER.

A view of the Seabotix ROV operating underwater studying the debris field of the HASSLER.

Dr. Hans Van Tilburg documenting the dimensions and orientation of the rudder of the HASSLER.

Dr. Hans Van Tilburg documenting the dimensions and orientation of the rudder of the HASSLER.

Dr. Hans Van Tilburg documenting the dimensions and orientation of the rudder of the HASSLER.

An unidentified artifact in the debris field of the HASSLER.

Archaeological crew on Eldred Rock with the lighthouse in the background. L. to R. - Hans Van Tilburg, Dave McMahan, Tane Casserley, and John Jensen.

The survey vessel LEGEND used to explore the remains of the S.S. CLARA NEVADA, formerly the United States Coast and Geodetic Survey Steamer HASSLER, which struck near this rock and sank on February 5, 1898.

Exploring a derelict wrecked on the reef

All that remains above water of an unnamed vessel wrecked on the reef long ago.

Remains of a once noble vessel that has been battered by waves and storm for decades

The wreck of the schooner E. B. ALLEN. Bow.

The wreck of the schooner E. B. ALLEN. Bow.

The wreck of the schooner E. B. ALLEN. Windlass.

The wreck of the steamer GRECIAN.

The wreck of the steamer MONTANA.

The wreck of an unidentified vessel. Bow and windlass.