Fast, high altitude tubular object with short uneven narrow contrail in clear skies with silvery body.Looking aprox SW, vehicle was headed approx. SSW and was visible over a 10 degree arc between 60 and 70 degrees above horizon. Short singular contrail from main body, body was thin, silvery or reflective , I did not see any wings as it was at a high altitude, it disappeared behind large cumulus cloud.I was walking on beach at time and usuually watch the airplanes coming in to land at nearby airport ( they are at 1 to 2000 feet about 1/2 mile off coast from where I saw this).I have seen airpanes at high altitude but with large wide contrails and am familiar with their speed and I would guess this one to be at least twice as fast as any I have seen.I called to my wife to look but she was 20 feet away and missed it.I estimate that other than a UFO, it could also be space junk in re-entry, or military , or ? I also do not know if airliners from Europe on route to SA fly over Bridgetown airport as a checkpoint.Contrail was short, uneven and evaporated quickly and stretched about 10 or 15 lenghts behind object and seemed to be uneven with apparent bubbles as if using pulses.Of course I had no camera and the event was so fast, I wouldn't have been able to focus it fast enough.I estimate body length to width ratio of 5:1 to 10:1.I am sending this from back home after the end of my vacation.Image is clear as a bell in my mind. I was not looking for it, it just captured my eye as I scanned the beautiful Caribbean sky .