I found this interview with Martin McElroy taken just after the GB 8 that he coached with Harry Mahon won gold at Sydney.

This is an extract in which he discusses testing equipment.

As an engineer by training I never take the status quo for granted. In the past crews mainly used empacher boats and concept oars. Was this because they were the best or because everybody was scared to do anything different? I didn't know the answer to that question or even if it was the right question. What I did know was that I'd like to test the hypothesis. It also concerned me that athletes got so hung up about equipment. Very few, if any, crews are constrained by their equipment. The differences due to equipment are so small compared to the impact of how a crew rows or how fit they are. Of course if there's any potential for advantage from equipment then I'd rather have it than not…

So, in the right context I set out to see what I could find with regards to equipment. Boats tend to be evolutions of something earlier. Things get lost in the mists of time. Why is it a particular shape? Just because something else was or because some serious research has been done. If research has been done, then what tools and methodologies were used. Are they correct and up to date? When you start to ask these questions there aren't many who can answer through progressive levels of questions. With regard to boats, Vespoli can answer quite a few questions. Carl Scragg, the naval architect has taken a good look at boats. Overall, I'd be more inclined to go with this than with data that originated in the former GDR. Things have changed a lot since then. Much more powerful computational tools are available…

I've done practical testing before and found the results questionable. Quite often the faster boat is the more uncomfortable. But does there come a point where being uncomfortable inhibits the athlete? As it happens the Vespoli is very comfortable but then most heavyweight boats are. With regard to oars, we used concept smoothies in '97 and then Croker slicks after that. Although I like the idea of adjustable handles, I found the early concept version required a lot of maintenance. I spent two days at the world championships in '97 changing inserts and grips. I didn't think that was the most productive use of my time. The more we used the Crokers the more we liked them. They sat very positively in the water right from the entry. I'm not fixed in my views about oars. Athletes adapt to oar types just as they do to rigging within reason…

A winning athlete doesn't leave anything to chance…. test, select and keep an open mind.