Early squaring can have a very significant effect on racing speed.
Also in the December 29 issue of the Rowing Biomechanics Newsletter Dr. Kleshnev reports on the effect of wind resistance on boat speed.
How significant can wind be?
"5 m/s head wind makes singles 17.4% slower and eights 12.2% slower, tail wind of the same speed makes singles 7.5% faster and eights 5.1% faster."
He briefly compares to World Championship results and suggests the research may somewhat overestimate the effect.
Perhaps most interesting is the significant effect of feathering and squaring of the blade - something we all know who have been in the boat, but perhaps not the extent:
"If the blade squared early at the middle of recovery, a crew can lose up to 10 s over 2k race at calm conditions and up to 30 s at head wind 5 m/s."