^^ I don't mean to sound patronising Chev, but I think it is pretty obvious what type of "maritime surveillance" is being conducted by drones in the channel, and I doubt the Poseidon would be the optimum platform (cost etc) for that type of close inshore role in the future. I would imagine/conjecture that a number of the roles us old jack of all trades Nimrod chaps/chapesses used to do, will now be conducted by other platforms - including drones - going forwards and thank **** for that frankly as some of those jobs were as boring as ****.
Given the number of aircraft/crews, I would again speculate that the P8 will stick to its core LRMP roles and training for them.