Volume - 35 Litres, 99 beers
Rails - unsure
i like it.
the planform template (top view) is very smooth in the nose area.
the 'bit of hip' at 1ft off the tail would look nicer if the curvature was a smoother in this area.
perhaps pull in the width here just enough to make the curvature smooth and continuous.
dont let me talk you out of it if you did this intentionally. its just my personal taste.
regarding the rails:
the profile you've shown is a good start for the mid section.
traditionally folks seem to start with 50/50 round rails in the front.
as you move aft the wide point moves lower in the profile to form a bit of tuck with a sharp release edge ( like your pic)
at the tail , widest part of the profile moves to the bottom, no more tuck, just sharp edge.
overall, in light of the boards width, i would thin the rails a bit by removing material from the deck side,
but opinions will vary.this is one aspect where you can search for 1000s of different rail designs on swaylocks.
the post below is a bit off topic, but you'll be asking yourself soon enough.