Tallsar,
Reference.... "Lee and Portland together do half the call outs of the busy places such as Prestwick, Chiv, Lossie, valley etc. ".
Individually both Lee and Portland do more callouts than Wattisham, Leconfield and Boulmer. One has done more than Lossie, and the combined total for Lee and Portland is considerably more than the busiest single flight.
Thus a single flight on the south coast could be expected to be by far and away the busiest in the UK.
The gap in coverage given the planned withdraw of Boulmer would be considerable, unless some of the other assets are planned to move slightly to compensate.