The two giant vessels, the tanker and the aircraft carrier, ride parallel, anywhere from ten to fifty feet apart, joined by a number of gigantic cables and held apart by huge airbags, like they squished a few blimps between them to keep them from rubbing. The heavy cables aren't just lashed from one ship to another; they've done something clever with weights and pulleys, he suspects, to allow for some slack when rough seas pull the ships opposite ways.