I was walking my dog in Signal Hill, Ca. which is a small city atop a hill which overlooks the City of Long Beach, Ca. From my vantage point, I could see into the ocean and I was looking in a S/W direction. At that time, I observed an extremely bright white light, a bit lower than normal aircraft altitude (maybe 4000’) and not adhering to what would be the the normal LAX or LBC flight path, which caught my attention. The light was over the ocean, appeared to flicker in intensity, much brighter than a star and the sun was still out at the time, but nearing sunset. It was possibly off the coast of Huntington Beach, Ca. As I watched, the object appeared to be completely motionless for about 6 minutes, then the light slowly dimmed and went out over the course of about 4 seconds. At that point, I could no longer see anything in the area. I don’t know how long it had been there before I saw it. Just looked up and there it was.