15 Hours in Transit at Sri Lanka. Whilst travelling to Singapore, we chose to have a long transit time at Srilanka. We acquired the ETA (electronic visa) online for free. After landing at Bandaranaike International airport, we headed to immigrations. We showed them our passports and next flight details and within 2 mins, without checking visa, transit visa for 2 days were stamped on our passport. We had pre-booked an agent residing in Colombo itself.