Correct. Having done some of this boring boat-spotting stuff on 35 Sqn as our secondary role, I can confirm that the 'LoPro' involved joining with a Canberra, updating its clockwork nav kit from the Vulcan's NBS by the highly secure method of reading out the lat/long over a UHF frequency
before despatching the Canberra off to identify something we'd seen on radar... I think we gave him the target's range and bearing from some reference point rather than giving him lat/long over the RT though...
The Canberra would descend towards the ocean, wind itself up to max chat and attempt to identify the surface contact visually. We expected that, should we ever have had to do this nonsense for real, probably all we would have heard would have been "It's a KrestaARGHHH!" as the Canberra was shot down.
'Selfpro' was much more fun and we once spent a happy few hours on a Solar Flare charging around the Mediterranean chasing Greek tankers which the nav team had selected as our target. Trouble was, we weren't deconflicted from other players and were soon on the receiving end of a snottygram from some boat person at some maritime HQ for having blundered into an area being used by a Nimrod which had been shadowing some Sovietski subski. Our DetCo back in Malta asked them why they hadn't warned us in advance and was stuffily told that their operations were 'secret'. "Tough $hit, sunshine, we'll be around for another week, so expect more of the same....CLICK!" was the response.