has anyone seen these before on their tubes?
the boat is only 2 years old. i have them on both sides of the boat and as you can see only below the waterline. the boat has been kept permanently on freshwater all this time if that makes any difference.
If, as I suspect, your "bumps" are the Hypalon outer skin, then it is probable that the fabric has in some way become porous between the inner and outer layers. I have not seen this before so maybe one of the forum's tube experts may provide the definitive answer.
Looks like a tube equivalent of osmosis. I wonder whether water or liquid comes out if you pop one (have a patch ready). I've got a couple of very slight blisters on the underside of my tubes where an extra layer has been glued on and trapped a little bit of air which has expanded in the sunshine.
