I also have been on a similar quest and i have thus far come across two compounds.
The component that allows mussels to stick to anything and under water no less is a chemical called Dopa, but i have come to learn that this is not a readily available compound, considering what it precursors
.
Secondly, a bacteria called Caulobacter crescentus is being called the strongest substance known (c. 2006).
These are the two i have been looking at and seem promising, but there doesn't seem to be any commercially available water based glue including either of these or anything close. Sorry i wasn't any help, just telling you where i have been.