Possibly Fisheries Protection Vessel "Watchful", originally built as Fairmile "B" Motor Launch "ML840", later "ML2840", 108 grt, built 1943, at Barry Docks, 1972. Scanned photograph taken with a Kowa SET.
<a rel="nofollow" class="external text" href="https://www.flickr.com/people/58433307@N08">Hugh Llewelyn</a> from Keynsham, UK
CC BY-SA 2.0
<a rel="nofollow" class="external text" href="https://www.flickr.com/photos/camperdown/9664310273/">Fairmile "B" Motor Launch</a>