Commercial vessels transiting the southern Red Sea and the Bab al-Mandab Strait are adding unusual notes to their public Automatic Identification System profiles—highlighting the crew’s nationality, religion or the absence of links to Israel—in an effort to dissuade Yemen’s Houthi movement from further attacks, shipping data show. The tactic follows the sinking of two ships by the Iran-aligned group earlier this week, the first fatal incidents after several months of relative calm. Houthi leaders have pledged to block passage for any company they deem connected to Israel, actions they say are in solidarity with Palestinians in the Gaza war. Maritime-security analysts call the AIS messages a sign of mounting desperation and doubt they will influence Houthi targeting decisions, noting that the militia struck a Chinese-operated tanker in 2024 despite earlier assurances. Insurance premiums for voyages through the corridor have more than doubled since the latest strikes, and daily sailings through the strait fell to 35 on July 10, compared with an average of 79 before the campaign began in late 2023.