Port2Port Chios Duathlon: A two-sport challenge combining cycling and running across Chios island. Start from Meston Port, 40km cycling through the island landscape, transition at Thymiania mixed zone, then 10km running to finish at Chios Port. Maximum 200 participants across all races. All registered athletes receive technical t-shirt, timing chip, race bib, commemorative gifts, trophy medal, refreshment stations, and ferry ticket return for athletes and accompanying persons (domestic routes only). Water stations at Kalamoti (20km cycling), transition zone (Thymiania), and at 3km, 5km, 7km of running. Drafting permitted on cycling leg. Road race with partial traffic control; full closures in neutral zone. Helmet mandatory. Mandatory briefing sent by email; no on-site technical briefing. Bike access: road bikes only, aerobars and time-trial helmets prohibited. Cycling leg cutoff 2:15. Online registration closes when the 200-athlete cap is reached. In-person registration on Friday 9 and Saturday 10 October at the Municipality of Chios building; no registration on race day. Race pack pickup at Chios Town Hall. Free bus transfers to the start points from the Chandris Hotel (duathlon bus departs 06:00, briefly stopping at the Thymiana transition zone); supervised bag storage at the finish (Chandris Hotel) from 05:30, no bag transfer from the starts. Contact: chiosrunning@gmail.com, skinos_cycling_team@yahoo.com, Viber/WhatsApp +30 6932 443 579.