In my ongoing analysis paralysis on a 14' downwinder (almost saved enough now so will have to plunge in very shortly) I am wondering about how important width is. I am specifically thinking about the DC 28.5" and 30" wide makuru models and Deep Ocean boards above 28". I am interested in weight/skill ranges - it will be my first downwinder.
iam unsure if this will help,
but i know, (from paddling both alot) that the Fanatic 12.6 X 27 is far faster then the 12'6 X 30.
ok yes the nose shape is different.
but the narrower model is considerably faster.
(both in carbon construct too.)
The one you will have the most fun on is the one you can stay on. No point in going narrower if your constantly falling off as you just won't enjoy it. If you have the ability to go narrower in my opinion it will be faster.
IMO..I think the rail shape.. and even the small edge on the rail itself.. and also bottom shape and even the outlile is more important than just the width as far as stability and down wind performance goes.
DJ
To finish first , first you must finish.... the combination of narrow width and tapered rails combinations definetly make the boards faster BUT if you can't stand on it what's the point. You need to be comfortable in offshore conditions to transfer all your power to your stoke and not to your legs to stop falling off.
It's because of this you see so many flat water boards now , serious racers have boards for inshore and offshore. In my opinion if you are new to downwinders wider the better.Dale has also tamed down the tapered rails which does make the boards much more stable.
1st downwinder and you really want to go at sea in most conditions.....go 30.
If you like the idea of going at sea but at the end will spend more time in flat water racing friends having narrower boards...then go narrow.
It's a bit like how many owners of 4X4 go off road? but if you do, then get something that works off road
There's no reason you cant go for Narrower boards for DW'ers for a first board look at the 17'4 bullet it's only 26 and something wide, Really it depends on your weight and balance ability!!! if you are 100kg but have great balance then you dont have to go wide!!! Guys like Piros would fall of a ship so they have to go a bit wider!!
i think 28 to 29 inches for 14 ft boards. as dj said shape and rails play a big part. personally i like edges from behind the middle to tail and i'm keener on a more planning nose then displacement. displacement tends to part the water and drop the nose down. something i don't want because a sup just isn't going to go through bumps like a ski or oci. i want the nose just sitting in the trough up the front. its either there to drop over the bump in front or its not imo.
i also think there is not point in having a bit of rocker. you either have a rockered board or the flater designs in vogue at the moment.
again personally i'm having a great time of it on my rocker planning nose, back 'edged' board- made to dw ---after you are really surfing on a decent dw er and this design concepts give me the control of a surfboard 
the tail rocker is important imo because when you stand back on a none rocker tail board the tail drags where a rocker tail still 'fits'. i'm finding it pays to hold back on the crest of the swell/bump and let the trough develop in front. i'm not noticing any drop in pace and your rested to really charge a section when its there to be had.
front nose rocker means you don't have to dart down the back or the board to 'save ' it all the time.
mind you one of the great thrills in sup dw ing is to be able to go back and be able to stay there on the good days
the longer boards you can generally drop down in width
cheers
disc just my thoughts
