There's an old saying that a real head
is ALWAYS mounted athwartships. That's so you can use it, or ride it, reasonably comfortably no matter how the boat is tacking or pitching.
Mounted forward, it means anyone using the head
has to traverse the whole cabin
, and if you use it as a wet locker or come below from the wet, you'll trek water
all the way through the cabin
. (I was terribly impressed by a Sabre
38 that had the head starboard side, just forward of the companionway
So if you're comfortable with the issues of having the head where it will move the most and require the most getting to...the only change I'd make is to put the head all the way up in the bow, where you have the water
heater. That way it will be athwartships.
I'd also suggest checking the venting requirements on the flash water heater--I know the guys and the boat where someone almost died from monoxide poisoning from one, that started the whole process of knocking them off the US marine
market for a long time. And just missed going along on that ride.