Just thought I'd share my aqualung making experience so far with you. I started making aqualungs at 100 skill, the first 6 attempts yielded 3 aqualungs and I gained 3 skill points. The next 3 attempts yielded 3 aqualungs and no skill gain. The next 6 attempts yielded 2 aqualungs and no skill gain. And my last 1 attempt yielded 1 aqualung and 1 skill point gain. I am now at 104 skill, have attempted to make 16 aqualungs, and have actually made 9. That's a 56.25% success rate for me so far. I hope it gets better.
On another note, I noticed that a slightly used aqualung will sell to the vendors for the same price as a fully charged aqualung. I was then curious to see if a fully used aqualung would sell to the vendor for the same amount as a fully charged aqualung, so I used up all the charges on an aqualung and brought a full one and an empty one to the vendor. To my surprise the vendor offrered me 190pp for each one. The value at the vendor did not decrease one single copper once the aqualung was completely used up. This was at a vendor who was indifferent to me and I had 115 charisma. My advice is that you let your customers know that they can sell the aqualungs to the vendor for a nice rebate when they are finished using it. Just my 2 cents. Good luck all you tinkerers!

Brillian Novaspire
31st Wizard Gnome
Solusek Ro