I still have the 3-D printed battery-trays from the last drone that flew back in the day, and it seems only right that they should be re-used here. I've parked them at the foot of each ESC on the head-board and tail-board, and as can be seen below the terminals will remain clear of the waterline throughout.
One reason that I like individual batteries to address the related speed-controllers is that it avoids connection errors in the field that short the packs out with a big BANG and leave you looking like Tom the cat in the cartoon after his house has exploded.
Another operational concern stemming from prior experience is that you want to be nowhere near the propellers at the point when batteries are connected, for obvious reasons ~ and with the boat stood on end like this, much of the deployment can be effected with the craft stood on its end... also good, in my case, for back and knees.
An additional advantage lies incidentally in the fact that the packs positioned where they are will lower the centre of gravity: with boats, as shopping, every little helps.
The white plug is used to charge the pack, one wire allocated to each cell, whilst the business end is the orange... which has the benefit of being able to be connected in one way only in order to avoid blowing up in your face.
