Agreed. We got off a boat less than two weeks ago--a 27m, 16-pax catamaran. All passenger cabins are on the main deck level, a few seconds away from the dive deck and with an door which afforded easy and quick access to the bow. I thought this was excellent. We were on another boat last fall, a steel monohull with all passenger cabins on a lower deck. Ladder access to the bow is unobstructed, and the route from our cabin toward the stern takes two U-turns. While we felt secure on the monohull, the cat seemed optimal, the more so because the passage from the cabins and the companionway from the salon to the dive deck are between the pontoons, which house the mechanical spaces.It simply reinforces my intention to always book a main deck cabin and carry a smoke and CO alarm.
As to batteries--On the catamaran, the captain permitted (only) cell phones, tablets and laptops to be charged in cabins, and only when attended; we were advised that if cabin crew found anything plugged in they would unplug it. On the monohull, no charging anything in cabins was permitted, and we were advised that (to my recollection) anything found charging in a cabin would be dispatched to the brine. Charging NiMH (Eneloop) batteries was permitted in the camera space adjacent to the dive deck, but all Li-Ion charging was restricted to the salon.
I think these approaches are laudable risk mitigators. But vessel owners have a real challenge, especially on a boat loaded with photographers, solving the problem of charging Li-Ion batteries, which continue to proliferate. Requiring all charging to occur in one area results in a mare's nest of wires and chargers, and outlets are in short supply, so power strips are common. A dedicated space in a watched area, with ample 110/220 service, would be an improvement.