I was just curious as to when the surface piercing prop was first used on a longtail motor. All indications would lead me to believe this occurred in Thailand and was linked to longtail boat racing. There is very little information regarding the history of the sport. The 150 cc motorcycle engines used on these boats would be one indicator as they have probably been around since the 60's. The Thais manufacture these propellers.
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The 60s sounds about right. That prop looks like the one that came with my 20 year old approximately 8 horsepower rated Thai long tail kit which wasn't meant for racing, according to the seller's advice of many years ago. The long tail part is pretty crude; it uses greased wooden bearings, with the grease needing to be be injected at regular intervals through a grease gun fitting. The Thai racing props and USA made surface piercing props do not resemble one another, from comparing those that I have seen anyway. I only used the kit one time, with a two horsepower electric motor many years ago and it has remained in storage, to be disposed of at auction along with some other boat things, in the next year. The Thai prop was way too inefficient for my particular project, though it might have the potential for Speed and could run in very shallow water, like mud motors do.
https://www.mudmotorkit.com/product-category/parts/propellers/