Interesting sighting, I'll say that. Historically rectangular UFO reports are not all that common, but aren't unheard of either. The problem is perspectives of witnesses relative to an object can sometimes affect the perceived shape of what is being viewed. Good example of this are the well publicized sightings of January 2000 over southern Illinois here in the US. The enormous object seen by many people (including several police officers) on the night in question was described by most as a triangle, but some reported it as a rectangle. Looking perpendicularly into one of the "legs" of a triangle, especially if it's going away from you, could give a rectangular impression.
http://activite-paranormale.net/NewRead-938-a black rectangular-shaped ufo seen in bolton.aps
The best example of a rectangular UFO I can remember was videoed several years ago in the UK (see above). Whatever this is, it looks to me like it is being blown through the air, as opposed to being under its own power. Sounds like crashing waves in the background, so it being windy locally is a reasonable assumption. But who knows.....?
http://activite-paranormale.net/NewRead-938-a black rectangular-shaped ufo seen in bolton.aps
The best example of a rectangular UFO I can remember was videoed several years ago in the UK (see above). Whatever this is, it looks to me like it is being blown through the air, as opposed to being under its own power. Sounds like crashing waves in the background, so it being windy locally is a reasonable assumption. But who knows.....?