You can comfortable operate BOTH a 75 Litre Fridge and a 75Litre Freezer with this combination:

Firstly choose the right refrigerator: An eutectic refrigerator would let you put it in the Boat and run off the eutectic system with the lowest power use.

Choose the Freezer: Use the second model Eutectic Fridge in Freezer Mode.

Combined they will consume about 60-80 Ahs per day with Typical Use.

Secondly power it with the largest Fuel Cell - a 2200W version. This will provide 186Ah per day maximum. It will produce the 8-9 Amps needed for both units to run. It weighs only 8kg and can be in a cabin or locker providing there is sufficent air flow for cooling. (We have a Kimberley "Australia Conditions" Kit that attaches to the fuel cell.)

Choose a moderately sized battery pack (140Ah would be fine) that would be directly connected to the Fuel Cell. The Fuel cell will automatically come on and charge the battery. The 2200W Fuel Cell will comfortable manage 2 Eutectic Fridges with one in Freezer mode.

Just set and forget...(replace 10Litre fuel cartridges after every 1 week continous fridge/freezer use)