Same experience on 16 Aug. I was all alone on the Ferry from Tap Mun on 13:45 (I pay $25 to get the whole ferry for my own use). At Plover Cove concrete island, Terns follow my Ferry for at least 20 minutes. Very exciting and I got many photos. I am sure some of you would enjoy my highly artistic and creative blur photos (wrongly focussed on the background all the time).
HF Cheung