Hi Fenals,
You need to look at the weight distribution onboard, and consider where that weight is located. For example on my B36/2002, I have a fuel tank on the starboard side under the aft starboard cabin berth, and a similarly sized fresh water tank under the port aft cabin berth. Also within the area of the main cabin I have two 225 amp hour batteries plus a single 80 amp hour battery under the starboard settee while under the port settee there are two 110 amp hour batteries. So if my fuel tank is full while the fresh water tank is only half full, it's most likely that the boat will have a starboard list. Even with both aft tanks full, there is still more weight of batteries on the starboard side, though the weight of the fresh water will be slightly more than the weight of the fuel. Think of the boat like a seesaw, both in the transverse as well as the fore and aft planes, and any increase in weight at one end of the seesaw compared with the other will result in it tipping towards the heavy side.
