It was round about one klm in diameter. Lighted panels a around under neath. They would illuminate seqentualy going round the base of it. I had a camera with video with me. But I was so terrified I could not use it all I could think of was being abducted and I did not want to give them any attention. I totally regret it now. It floated above the Mackay bridge in Halifax. I quickly made my way back to the safety of my ship. (Canadian Coast Guard). I could draw you a rough sketch if you want. I never heard of a UFO being that size.this happened about March 2011. But just finally told someone (my wife) I did not anyone think I was mentally unstable. The incident date is a rough guess. I can narrow it in a little by log books. This object was as big as I said. I have no reason to msakeup such a story.