red lights in fixed triangular arrangement, slow rotation, straight flight path, low level late evening, friends were visiting by boat on the lake and we were talking to them from the patio/dock on west side of property. there was a strong and warm wind from the north west. clear skies. when our friends left for home in their boat, I was the first person to walk back towards the house. (mom and dad were still at the dock). as i was walking I noticed red lights moving above the tree line behind the house. it was moving towards the south east, and slowly dipping behind the tree line and behind the house. I walked around the house to keep my view of it until it was no longer visible due to treeline. as it went in a straight line, it appeared to rotate very slowly CCW. the duration of the sighting was approximately 30 seconds to 1 minute. we were living temporarily at this property while our home was being constructed just up the lake (north). I was very familiar with air traffic in the area as it is within the air traffic control zone of CYHZ air port (halifax international). where the house was being built is the location of our cottage, which is directly under the YHZ approach/takeoff line for the 143* runway, so air traffic while at the cottage was constantly overhead. At the time (i was just a kid), I was very aware that the lights were not standard for such apparent low level flight, especially within proximity to an international airport. Now, I am an Aircraft Maintenance Engineer, specializing in helicopters. and I am very aware of lighting requirements for aircraft flying under Canadian Aviation Regulations, as well as what a helicopter or airplane would look and sound like. most notably, the spacing of the three lights were equidistant, and i saw no aircraft structure obstructing any of the lights for the duration of the sighting. this would imply all three lights were on a presumably flat bottomed craft. I could not see any of the crafts structure, whatsoever. there were no NAV lights (red, green, white), no anti-collision/ rotating beacons, and no flood lights or landing lights of any colour. the craft did not make any noise that I could hear. granted the wind was reasonably strong from the north west, there were large waves braking on the shore next to me, and wind in trees; which would impede the aircraft sound reaching me.