What is clear then is that I will need to have a network of local consumer units fed from the utility room consumer unit. This will also provide a few advantages (but not cost ones), The main one being that tripping a consumer unit (as seems to happen regularly) will not trip the whole ship (I am guessing). It should also mean that I can run lighting locally so a tip will not wipe out the entire ship lighting but just local areas. Not a major issue. I am considering one unit for each of the cabin areas (so no stairs are required to reset a tripped MCB), one for the mess and toilets and bathroom. One for the kitchen and lights. One for the wheel house, radio room and battery room. Finally one for the main chain room and front bedroom (as it will be).
The advantages are that I will not need to run hundreds of cables out of the utility room to various places but single cables (I think) to the satellite consumer units (the viability of this to be looked into). My theory is the less cable running around the better.