Images used by permission; copyright is retained by respective owners, listed below:

• Emory Kristof: underwater photographs of RMS Titanic and artefacts on seafloor
• Black Smokers: photo provided by Andrew Wight / Earthship Productions
• Ken Marschall: artwork of sunken Bismarck
• Deep Ocean Expeditions: underwater submersible operations photos; images of MV Alucia shot by Neil Rabinowitz
• DeepSeaPhotography.com: deepwater animals, Keldysh and Mir topside shots
• Public Domain: archival (B&W) images of Titanic, Bismarck and Jules Verne