no it is not seamless. maybe in the sense that they are very well hidden, but how could you fashion a drysuit out of a single piece of neoprene.
As a matter of fact, we just got it back yesterday from BARE. They indeed found it was leaking through several of the seams. Hopefully the repairs took care of it all.
When using the word seams, it means a needle pinching 2 pieces of neoprene together.
They use a none stitching way to assemble the suit. So there are no hole where the water can come from.