I was looking out of window at some lovely clouds when something in clear blue sky in between the clouds caught my eye. it was small egg/round shape and all black, at first it travelled as an airplane would but then it dived down, back up quite erratically and then continued on same path. it then did some more manoeuvre's that would rule this out being an airplane. after about 3 minutes the object just seemed to disappear into a cloud, but i did see the object pass under clouds so while observing it was just below clouds when flying. at one point it did seem to hover for a few seconds close to a cloud. i did think it could be space station or similar but i could see object below clouds. i also thought it could be a weather balloon, but again the way the object moved at times would rule this out. also the clouds were moving from right to left in my line of sight the object was flying against the wind from left to right. so i am not sure what it was that is why i decided to write this report. it looked like it was solid and black. about 10 to 15 minutes after event i could here raf planes flying close, but that is quite common for this area. i will also add the sun was out at times of viewing the object and it did not seem to reflect light when in clear blue sky or just under clouds, it just remained black at all times. i did not feel frightened while viewing object, it was just very odd.