Probably because there is not much for the submersibles to do, other than a couple to monitor things. You don't keep expensive equipment like that "at depth" unless they are actively working.....too many things to go wrong.
Agree. But they could have a few showing what they are doing at the seabed floor regarding the leak in one of the lower valves within the lower subsea floor casement. Then again, maybe they are doing nothing in that regards. The last statement was not meant as negative. Maybe they have to obtain a new valve or valve gasket etc., before any repair can be started.