I've done both Aquacat out of the Bahamas, and Spoilsport in the GBR - they are possibly sister boats - both are very similar layout catamarans. All steel.
Guest berthing on both are staterooms with windows, with the exception that each has one odd-ball bunk-bed cabin at the front that's sort of in the middle. Aquacat's room 11 has a skylight, Spoilsport's has no windows. The rest of the cabins all had large windows.
On both boats, the quest cabins are on the same deck as the dive deck - the deck directly over the left and right side hulls. It's been a while, and I don't recall if/what forward exit there was from this deck (the main passage was to a water tight door out onto the dive deck).
The crew cabins, along with the major mechanicals, are in the left and right hulls. I don't recall what, if any, secondary egress options they have from down there - possibly a hatch out to the area were the anchors are? Primary access was down stairs roughly 1/3 of the way into the hallway where the guest cabin open into.
Next deck up was the salon & galley. On Spoilsport, this was also where the wheelhouse (incl. captain's berth?) is, as I recall. On Aquacat there's a forward watertight door that opens onto a small open deck that guest are allowed to use.
Aquacat's top deck has the wheelhouse and an open-air deck (and a bar). Spoilsport's top deck was all open, half shaded -- we took gear up there on the last day to dry.