I Bought a Schill spool from Germany to use as tetherdrum and slipring from China and drilled a hole in senter to be able to get the cables out. I have attached a 10m deckcable directly from the sliprings and to the fathom-x board inside a closed box to minimize the risk for waterpenetration in connectors and this alowes me to have the fathom card close to the computer in dry invirements. I also bought a nice small cellum grip for the tether and made a senterpoint for it to be attached to.
I also installed some small brackets to keep the battery enclosure secured during diving.
The reason for my lightmount solotion was to minimize the risk of damaging them on the outside.
I have allready ordered two BR switches to be able to power it down without taking the batty out.