I was sitting on my lanai tonight when I happened to look over the trees. I saw an object that was glowing white with one each red and green, very bright, non-strobing lights. As soon as I saw it, it immediately sped NW at, what I took to be in excess of 200 mph. Suddenly, it stopped. It did not slow down, it just stopped. After a second or two, it sped off on a 45 degree tangent. It did not ramp up to speed, it simply appeared to reach high speed immediately. It did this abrupt start and stop with direction change two more times. Then it hovered for a few seconds and descended in a vertical line behind the tree line. Not as fast as before. Perhaps twice as fast as a helicopter. I waited for a half minute or so and it ascended in a vertical line, paused for a couple of seconds, then descended again. I have not seen it again. My wife also witnessed a portion of this sighting. I spent my Navy career (retired) in Naval aviation and am familiar with most types of aircraft. What this object did is, I believe, beyond current capabilities. As to my emotions, I was initially unsure, but when I saw the extraordinary maneuvers, I was sure that I was seeing a UFO. Unfortunately, I was too entranced to even think about grabbing a camera or cell phone. Henceforth, I will have my cell phone with me on the lanai at all times.