Your article on Qinetiq's Sentry surveillance craft (The Big Picture, 1 October) was interesting.
Amusingly the photograph accompanying it (perhaps because it was a sea trial) shows this vessel of 'speed and agility' displaying the internationally recognised shapes for 'a vessel restricted in its ability to manoeuvre'.
Martin Figg
Weymouth
PMI falls as manufacturers feel the squeeze
17 months or two and a half years - which is it?