Them blasted conch shells!

I'm looking for conch shells so I can have some of those diving devices made for the underwater city. The problem is that I've only found 2. Are these in random locations on the map, dropped by monsters, underwater / beaches?
The ones I found were lying near the town wharf. I haven't found any since and I've completely mapped the area.

Help appreciated.

ogdoskey

Go for them darn crabs. Sometimes (not often) they drop a shell when they die. But don't get too worried. I did half of Collasium with a single fightring character who had the 'iron lung' trait and a helmet. While there I got three shells and went back to B.Roon where I added my best spell user with a helmet and breathing shell. These two finished Collasium and I'm off to Cet's pyramid tonite. The only serious nasty was the 'Mother of Crabs' but liberal use of 'Burning Haze' at a safe distance was enough to sort her out.