I tried finding a similar issue among the other threads and could not so I apologize if I am being redundant. Being a pessimist I always keep a spare prop on our boats, along with whatever tools ae needed to install the prop (spare cotter pin, pliers, wrench, etc.). normally, being a back-up prop in case the one on the boat is damaged, I try to economize by buying the cheapest prop of the same size. This would normally be a comp (composition) prop. Solas and other companies have a decent reputation in this area. However, you probably would have to also buy a hub kit that adapts the spare to your engine. While I have replaced props using hub kits a problem could arise if you needed to change the prop while on the water. This is not the most ideal position to be in. A tip in the case the water is too deep to stand up in comfortable: wear your life vest upside down like a diaper. This will float you chest high and make it easier to work. This is also a comfortable way to float in the water when parking in a bay and having beverages. Over time I have come to the conclusion that it might be more practical and possibly just as economical to buy an OEM replacement prop and not have to deal with a hub kit. Also, if your spare is a comp prop you would still want to buy a new main prop. Now my logic works best if you are using an aluminum prop. They are more likely to ding than a stainless steel one. If you ding an aluminum prop it is a simple matter to switch to the OEM prop and if you can file down the ding, let the old prop become your replacement and not have to switch props again. If you are running a stainless steel prop in good shape I would still buy an OEM aluminum prop since stainless props don't ding heavily and can be machined to satisfactory tolerances. Experience: In august of 2017 my wife (honestly, she is the only one that drives) hit a floating object on KY Lake that took a decent chunk out of our aluminum prop. We have a 2018 24SLX tritoon with a 150 Yamaha and run aluminum props due to the shallowness of the lake. You could definitely feel a vibration at higher speeds, say around 30 mph but the prop is still useable. In trying to find a replacement prop the dealer said they were back ordered from Yamaha. I got on Amazon and found an OEM for less money. I swapped props and filed the ding on the old prop and made it our spare. Now if we ding the new prop as well I at least have a spare for emergencies and then will have to buy a new OEM prop.