During my service in the U.S. Navy I witnessed a strange unexplainable event while in transit back to our home port of San Diego from rimpac 2010 multi national naval exercises. Course and speed was roughly 010 true @15 kits. The date was approximately 8/4/2010 time about 2215. I had just finished my watch in sonar control and went to the smoke deck on our starboard quarter (aka starboard break). I was not alone, however, I do not remember how many people or who was there that also witnessed the event. I saw a medium sized ball of light about 10 or 20 feet above water approximately 3kyds away almost as soon as I got there. Initially I thought it was another ship that was also in transit and continued to observe it because to my knowledge we were alone in transit on our Pim. (Strike group commander set course and speed). It was mirroring our course and speed almost exactly with no discernable difference to our own for a period of about 15 minutes. The ball then traveled very rapidly from a forward position relative to my ship to aft then changed elevation and rose vertically nearly instantly to an elevation of about 200 feet or so from my perspective. It then appeared to mirror our course and speed from that elevation and follow us. Startled and perplexed I put out my cigarette and went directly to the cic (combat information center) to report what I had seen to the cic watch officer and radar operators. I told the cicwo my findings and was brushed off. I then went to the sps-49 radar operator and he had apparently had overheard my story. The petty officer on watch proceeded to show me that he had contact on the surface and air search radar that corresponded to what I had witnessed. He also told me that same chain of events has been reported 3 other times by other individuals and had been occurring since our transit had begun 2 days prior. I do not recall if the incidents had been logged or not in the cic watch contact log. I seem to recall being told by this petty officer that they were instructed to maintain contact and observe its movements but dont bother logging it as it didn't appear hostile or of any interest. I was also told by him that the past 2 nights they had lost contact due to extreme elevation at about the same time each night. A few hours before dawn. Oddly enough during the actual rimpac exercises my ship as well as every other ship in our strike group experienced strange connectivity and communication issues. An investigation was launched by the strike group commander under the premise that there was suspected probe initiated by the Chinese on our entire strike group. I later discovered that the comms and systems phenomenon the ships experienced had no explainable origin and no evidence of an attack from a foreign nation was detected.