According to Kovalenko, this was an intentional form of "naval diplomacy", carried out with the aim of asserting the Ukrainian claim to the surrounding waters. While the ships received pilot services from the Kerch port authority free of charge, they were also tailed by at least 13 Russian vessels, and flown over by Russian aircraft.[40] Ultimately, the Ukrainian vessels complied with transit procedures which did not require a request for permission to transit,[42][43] Russia did not hinder the ships' passage under the Crimean Bridge, and they successfully reached Mariupol. In an interview with the Kyiv Post, Ukrainian naval expert Taras Chmut said that he thought that Russians had not expected the Ukrainian operation, and so decided to take the least risky option by allowing them through.