I am in Panama City at the moment, and looked into the options here. I am bringing my bike down to Girag tomorrow morining and they are flying it for me. Quoted me $551.25 all inclusive.
Booked a seperate flight with Copa for me and that was $240 after tax. I was in Portobelo today and was taking to this guy that just came over on a yacht. Sorry cant remember his name, but was saying he was charged $550 for the three day trip by boat.
Personally i think the flight is safer, faster and you dont get salt water on your machine.
Number for Girag is Phone at Tocumen(Airport office): +507 238-4326 and In Bogota: 571-414-7010
Hope this helps. But there are yachts that go from Portobelo, but you have to ask, and its not guaranteed, and the town itself is tiny.