fillman wrote:Is hull sweating common?
If you mean. "Does water from the inside a Boston Whaler Unibond hull suddenly pass through the gel coat resin layer and appear all over and rather uniformly on the outside of the hull?" then, no, that is not a common occurrence.
The gel coat resin layer is mostly a non-permeable layer. It is possible with continuous and prolonged immersion in water that the gel coat layer might absorb some water. This is the behavior that leads to the condition of the gel coat known as osmotic blistering.
With Boston Whaler boats, osmotic blistering has not been a problem that has been reported frequently. Note that Boston Whaler recommended in their owner's literature that the portion of a hull that was below the water line on any boat that would remain in the water for more than few days be top coated with a two-part epoxy paint as a barrier coat. Such a barrier coat would enhance the characteristic of the gel coat layer to remain impermeable to water.
Generally if a hull has any entrapped water, the only external visual manifestation of the entrapped water would occur at some place where the gel coat layer was damaged, and if the damage was at a low point so water flowed their by gravity, water would be seen seeping or weeping from the hull.