When one gets into a boat, especially a trimly designed racing craft, instinctively the muscles of the body tense up, as the brain sends messages that you are not on stable surface. This is of course more true with beginners and the less experienced. This tension often manifests itself in the rower tending to grip the oar handle excessively, thereby causing tension in the forearm, which transmits itself to the rest of body resulting in poor flexibility and coordination.
One of the skills a rower has to develop from day one; is the ability to relax, when in the boat. A good place to start is the manner in which one grips the oar handle, both through the water and up the slide.
Through the water (Drive Phase)
When through the water, especially in the first half of the drive, the hands merely act as a link to the oar handle to transmit the power generated from the legs. The hands never really grip the handle. The fingers merely go over the contour of the handle like a hook and while drawing, the wrists would be flat and one is likely to see a little space between the thumb and the handle (see picture below). A good exercise (in sweep rowing) to ensure you do not grip, is to row with your thumbs moved up and along the axis of the handle.
Up the slide (Recovery Phase)
The recovery phase is when the rower should be totally relaxed, so as to take advantage of the little rest he gets on his way up the slide. To enable this, the hands merely rest on the handle (see picture below), only applying the weight that is required to maintain the desired handle height. The oar is left free to rest on the rowlock. It is important that the wrists are not kept dropped too much, but moves up after the feathering process, to assume a flatter position. A good way to feather, is to feel the handle being rolled on to your fingers rather than the wrist breaking excessively.