Slipknot (photo by Raymond Ahner); Coheed and Cambria (photo by Thaib A. Wahab); KISS (photo by Kevin RC Wilson Planned 2020 rock cruises led by Slipknot, Coheed and Cambria, and KISS have all been postponed until 2021 due to the COVID-19 pandemic, as announced Thursday by the events’ producer Sixthman. A number of the production company’s other cruises and vacation festivals have also been moved to next year. Slipknot had already announced that their Knotfest at Sea cruise would be postponed, but now some specific details have been revealed. Instead of setting sail from Barcelona, Spain, as it was scheduled to do this August, Knotfest at Sea will now depart from Athens, Greece in August 2021. Exact dates will be announced shortly. In addition to Slipknot, the 2020 lineup was to feature Be...