A wetsuit includes an outer layer and an inner layer. The inner layer is attached to the outer layer and includes a plurality of fibers having wool and being configured in a plurality of clusters. The inner layer also includes a plurality of interconnected channels. At least a portion of each channel is defined by a space between adjacent clusters. The wetsuit also includes an opening that is disposed on a rear side of the wetsuit. The wetsuit additionally includes at least one fastener that is connected to the opening to open and close the opening.