Can't believe about the watch issue. I personally have been able to carry a watch every time. But yes, invigilator may as you to take it off and in that case, usually there is a watch in the classroom.
As rashiv has suggested, it is okay to ask the teacher for the time. From time2time
My centre had a broken bench, a dim light and the invigilator got agitated after I asked her for the time more than 3 times. I got used to practicing the paper continuously looking at the watch, gonna practice without it now
