I don't want to cut down trees either.
But if to plan ahead for re-growth,
and if the ships are lasting.
And to be re-used to multi-purpose.
Primarily to save marine life,
preserve species,
and help aid food shortages.....
Then worthy.
Rather the handheld router (which is entirely possible)
A large hollow cube CNC machine can be a base
for the interlocked wooden beams as rectangle
can be placed inside, for very quick cut outs
but as i write this, the angles are limited.
handheld router it is.
Ship interior is bit more complicated.
Though not impossible for automation.
If sides were shaped by the CNC machine,
followed by the compartments from top to bottom,
But only after the first layer of whichever required
depth is separated by a very long saw. (To later
cover the hollowed out compartments as roof)
But it is best to just use the handheld router instead.
It wouldn't take long anyway.
But if to use specifically to cut the sides of the
rectangle to form the outer surface of the ship (the CNC)
then yes, that would certainly save a lot of time.
The long saw, can be fixed on two pillars of the CNC,
and following a horizontal line which moves up and down
as required. if a 'layer' is required of the rectangle.