The effects that summer and winter operations can have on the expenditure of sonobuoys is quite dramatic.
The presence of a temperature decrease (thermocline) during the summertime in the top 300ft can make the cat and mouse localisation and tracking of a submarine very difficult. The subsequent increased expenditure in sonobuoys would be a major problem for UAVs.
Working in industry, it really is pie in the sky to make bold statements about capability, which only exists on a bit of paper. If the managers say 5 years for a system, you can double it and add a bit, unless of course, you throw vast amounts of money at it, as the US have done in the past.
Not sure whether they will be doing that soon, as their budget deficit is just about to hit industry over there as well.
PS It feels that my time spent on Nimrods was sort of wasted, by a decision to scrap the capability. Something in me feels empty, in the decision to close Kinloss, and I wish all the best to the folks up there. Sad sad times.