Yes, was in my mate's "BIKE". Registration has something to do with previous owner and his occupation.
As far as other traffic was concerned, there was not just little on ADS-B, but very few seemed to be working Southend or Norwich (Wattisham was closed of course). Most activity we heard was people out of Ludham, and then we met 2 (non-radio obviously) paragliders towards Southend on return. Maybe we were just too early going out in the morning, and everyone was home early in case the fog came in.
Either way, it was a superb flying day without a bump to be found.