My answer is for our 2005 H38, but layout is mostly similar by manufacturers. Under the port hanging locker there is a tube with cables from the rear end of the boat, running from there to under the seat at the nav station.
There is another tube holding cabling that runs also on port, it is at the height of the joint between hull and deck. It starts further back under the ceiling in the aft stateroom and finishes behind just in front of the vanity bulkhead. It is more hidden on the nav station side and getting to it on that side is not easy.