Often, when discussing various specifications for our designs, I will be asked what our A/B ratio is? (we don’t list it in our specifications) I then have to explain (or try to explain) why the A/B ratio is a meaningless number. The problem is many other successful trawler builders tout the A/B ratio of their models and have convinced their owners and would-be clients it is something of significance.
I first read Voyaging Under Power (Robert Beebe, Jim Leishman, Third Edition, 1994), in the middle ’90s, before I got into the boat business. When I got to the part about the A/B ratio, it just didn’t make sense to me. My first thought was even with a higher A/B ratio, the beam of the boat or the shape of the hull was not being considered. At the time, I let it go.
Well, fast forward a few years and I had a discussion with my good friend (and our designer), Steve Seaton about the A/B ratio. His first comment was, “don’t get me started”. Well, we did start and discuss it at length. I found my thoughts way back then were pretty much “spot on” and the A/B ratio was pretty useless.
In the time since, I have found several other credible designers all seem to agree with Steve. But strange as it seems, many other trawler builders still list a specification for their A/B ratio………..go figure.
To read Steve’s paper on A/B ratio, click on the link button: .[button_link url=”https://northwestyachts.com/wp-content/uploads/2012/03/A-B-Ratio-Seaton.pdf” target=”” style=”” title=”” class=”” id=”” onclick=””]A/B Ratio is a Myth[/button_link]
So……if you ask me what our A/B ratio is in the future, I will probably say what Steve says, “heck if I know”.