He wrote me last year and it was stuck in my craw ever since.....
"the performance of a ⅞” thick hollow flex fin does work better on shoulder high or better waves than a standard ⅜” thick flex fin at a much higher price point than Larry’s ($200ea) if you are looking for something hand built and of exceptional quality with the extra cash then order one - if your on a tighter budget than Larry’s flex fins are hard to beat for the price. Hope this helps"
Not sure what board you want it for, but I got this from Gene a while back:
I don't go for thick base fins on standard noseriders because I've found they tend to drag. Tail rocker plus a soft edge plus a thick fin just tends to accentuate the effects of the tail rocker and slows down the board. Too much of a good thing.
To the contrary, when a board has hard edges in the tail and moderate to low tail rocker then the thick base tends to set the tail, engaging the edges. The board feels more engaged overall and looser since tracking is minimized. Efficient with reduced drag.
These are my opinions based on the long term use of thick bases, the scientific fin theory guys may come to different conclusions.