Hi there I managed to print schedule out, the bus only goes to Chetumal, then grab a cab to the border. The bus in Playa DOES NOT leave from the terminal on 5th Ave, it leaves from the other terminal near 20th & 12th. Here are dep times..
00:00,00:25, 01:50, 6:20, 7:20, 9:20,10;50, 11:50, 13:20, 14:35, 15:20, 16:35, 17:35, 18:25, 19:35, 21:20, 22:35...Also some buses make more stops so the travel time is longer, I am going to try taking the 6:20 am bus to try and make the 11:30 flight in Corozal next week, I hope its do able, time will tell...Hope this helps...Cheers, LaGrange