That's gotta come sometime soon - practically impossible to gauge strength from weight alone - 

As far as I can tell, the bigger brands (who also make Windsurf boards) all list the volumes of their boards. Not that it matters to most surfers, as surfboards never have volumes listed. But as we are dealing with way different construction and usage, I see the point that some people want to know the volumes. I know Starboard, Hobie and Naish list all their volumes. Most of the custom shapers and smaller brands do not.

Right now I ride a Naish 11'4" (for smaller days and downwinders) and just got the new Naish Mana 10'0". I tried my friend's Mana a few weeks ago and fell in love with it - so I had to get one for myself. It is by far one of the easiest boards to ride (it is 32" wide, which makes even the kookiest kook feel stable). It is also really manuverable in the waves. I haven't tried it is big surf, but in shoulder to head high it is a dream to ride. And the wife likes it as it is a lot more agile to turn than the 11'4".

What do you ride Shortboarder?

The Mana 10 is around 4 3/4" thick I think. Doesn't seem too bad because the rails are slightly tapered (and the board is really light). I must say I was really surprised by this board. It didn't seem possible to be as stable as it is and as "surfy" too. But somehow they managed to get it just right in my opinion. I have also heard that the Mana 9'5" is a blast for smaller riders. I think this is the trend nowadays... 9ish footers that are a bit wider and have a bit more volume and rocker.

Nope, the Mana has an EPS core and Biaxial glass/wood veneer sandwich deck and bottom (according to their website). The white deck is a bit deceiving as it kind of looks like the other AST models. But I assure you it ain't heavy for how much volume it has. My wife is 5'2" and she can carry it no problem.