The debate in gig rowing is about how large the arc should be from the orthogonal to the extraction. In sliding seat rowing where all the leading rowing nations have equipment which can measure actual arc angles, force:time curves, boat speed and fluctuation, etc., etc., it has been known since the 1970’s, if not before, that arcs in excess of 37 to 40 degrees from the orthogonal to the extraction result in less efficiency – the boats are shown to slow-down when the arc is over-long, as the boat (now moving at its peak speed) effectively ‘tows the blade out of the inside of the puddle’.

Since the 2000 Olympic Games, the increasing sophistication of the measuring equipment, and the fact that many more National Rowing Teams have access to such equipment on a daily basis, has actually led to a further reduction to the optimum arc from 37 to 35 degrees.

In sliding seat sculling (each person using a pair of sculls), this angle has to be larger, simply because it is impossible to reduce it, except by making other compromises to the stroke which in turn result in slower boat speed.

The over-long finishing arcs used by many gig rowers may have resulted from the early days of the resurgence of the sport when there were very few rowers left from the post-war days to offer guidance, and, (to our knowledge), there hasn’t been any bio-mechanical analysing equipment designed for fixed-pin/fixed-seat rowing. When gig rowing used oars with a very long inboard length (pre-1960’s), the arc angle from the orthogonal to the extraction had to be much less than during the 1970′s until the present, because the long inboard lengths physically restricted the finish arc.

Also, in all the other branches of fixed-seat rowing (that we are aware of), none use the over-longer finish arc used by gig rowers.

At some stage GigRower may produce another article on the bio-mechanical analysis of the blade in the water from the catch to the extraction, in conjunction with the acceleration/deceleration of the boat, but first the series of articles on ‘Choosing Oars’ needs to be completed! (Ed).