If buyers today become more willing and able than before to purchase larger quantities of stand up paddle boards (SUPs) at each price of SUPs, then

This simply implies an increase in the demand of Stand Up Paddle boards at each price of SUPs and an increase in the demand would mean a rightward shift in the demand curve for stand up paddle boards. Usually a rightward shift in the demand curve is caused by a couple of factors such as a increase is income, a fall in price of a complement product, or increase in the price of another product that can be used as a substitute.